There are so many people who've worked on this, if you say "I did!", they come out of the woodwork and say "NO, I did!" This almost caused a fistfight (Ed B. vs. Jim P.), at Type90 in Oxford, so, that's all I'm gonna say. Ask The Times, they'll give you the "official" story?

Not to split hairs, but technically isn't that the nameplate, not the masthead?

Masthead: The part of the newspaper where the names of the officers, editors, etc., are listed.

Nameplate or Flag: The decorative rendering of the newspaper name, on the front page, often a logo.

History: The names of a ships owners were traditionally engraved on a brass plate nailed to the mast of a sailing ship in old days. The term masthead was moved from shipping to the newspapers.

The term is often misused, but if Stephan is doing research, hopefully he will find this information of use.

Thanks for the terminological clarifications - as a non native speaker I was appearently mislead following some of the misuse cases of "newspaper masthead". Regarding my research: I thought that there had to be some research been done already (though I did not suspect the subject would have approached causing fistfights), that's why I asked in the first place. And my topic is not the NYT nameplate itself (no danger of me saying "I did!"), but a book cover that was designed to resemble it:

A couple of years ago, I was at a talk Benguiat gave at FIT, and he mentioned that his redesign of the New York Times nameplate was to drop the period -- he also mentioned that the paper lost about 1,000 subscriptions when that happened!

The date of the elimination of the period was: February 21, 1967.

Following is the text of an extensive ongoing document - it's almost a blog - by "Character" on the subject of the NYTimes nameplate. He posted this update a little earlier today. It includes a timeline of changes. Copies of all the referenced nameplates can be found in the on-line archives:

VERSION 7 May 2006

Here is my standard text on the subject (with some input from Dick Margulis):

FONT:

From "Facts about the New York Times", which used to be available as:
Facts_About_NYT.pdf: A version now available doesn't include this information (and I never saved the version with this quote).

"The New York Times logo [known as the Nameplate], which appears at the top of the page, is hand-drawn, copyrighted and cannot be reproduced without permission."

The Nameplate was first created about 150 years ago and consisted only of the letters actually used.

Therefore there is no official matching font.

The nameplate itself has undergone numerous modifications since then, and its alphabet has expanded by other usages in the newspaper and its corporation.

The closest generally available full font appears to be "English Towne". However, the variations between this and the actual logo are unsubtle and numerous - missing diamonds on the thin verticals, a different termination on the minuscule "h", major differences in the minuscule "e", horizontal connectors on the majuscule "N", etc. About all that could be said is that it has the same general "feel". Every now and then you'll see someone state that "Becket" or "Becker" is the font, but even a cursory glance shows that this is absolutely nothing like it. This was a comment that someone posted years ago and the internet has preserved for posterity.

A complete version of English Towne, enhanced by Dieter Steffmann, can be viewed and downloaded from typoasis
http://www.moorstation.org/typoasis/designers/steffmann/index.htm

A truetype font was created by an unknown author, consisting of ONLY the letters in "The New York times (T, N, Y, h, e, w, o, r, k, i, m, and s), as they appeared in the 1990's.

HypoTypo extended the font by estimating the remainder of the lower case letters (NewYorkTimesEnhanced.ttf). Of the a, g, n, and z that are in the word "Magazine", Hypo's guesswork was superb for the a, g, and n, but not the z. That font, with a half-dozen uppercase characters and a full lower case, is available.

I have been slowly (VERY slowly) working on creating a more complete font, including characters from the sources shown below.

HISTORY OF THE NAMEPLATE

Logo Timeline
1851 Sept 18 New-York Daily Times, Volume 1, Number 1
2 Different Blackletter logos used, one for the large Nameplate, and a different one for smaller nameplates on the same page. Day and date appear on each page in blackletter, which is how it will appear through Jan. 14, 1894.
1857 Sept 14 Name changed to The New-York Times; different lettering
1884 Jan 6 Changes to nameplate - most noticeable on the N, r, and s
1894 Jan 15 Changes to nameplate - Major revision in the overall look; Date no longer blackletter.
Note-The changes are not reflected on that day on the masthead on the editorial page.
1896 Dec 1 Hyphen removed from New-York
1914 Dec 30 - Beginning of a subtle change to the tail of the "h"
1967 February 21 Major redesign of the logo by Ed Benguiat; period removed, Date now in all-caps italics. All characters changed - lines made thinner, T gets a diamond instead of a caret, Y is expanded, and more.

There were five additional characters introduced with the word "Magazine", based on the cover of the Sunday NY Times Magazine section (M, a, g, z, and n). The magazine's nameplate also introduces varieties of the "e" and "i" that are different from the corresponding letters on the front page. In fact, if you look closely at "The New York Times Magazine", the e's in "The" and "New" are different from the e's in Times and Magazine! The differences are in the small straight line spurs. The letterspacing differs between the front page "The New York Times" and "The New York Times" as it heads the magazine section.

Since its acquisition by the New York Times, The International Herald Tribune has used exactly the same typeface; this adds the characters H, l, d, b, and u.

The New York Times Style Magazine was introduced August 29, 2004, adding S,y, and l to the alphabet, and introducing an alternate display "T", created by Matthew Carter.

In September, 2005, a feature called "The Talk" was added to Style Magazine. This currently provides three lower-case words in each issue, in the same NYTimes blackletter. But there are some subtle differences; the e and o, for instance, have lost their spurs. Thus far (as of May 7, 2006, after eleven issues) these letters have been included:
a, b, c, d, e, f, g, h, i, j, l, m, n, o, p, r, s, t, u, v, w, x, y, and ï (i-diaresis). Some additional upper and lower-case letters may be inferred from issues of the paper prior to 1894, when the date was displayed in the same blackletter.

In the 1920's, at least the Rotogravure picture section of the sunday paper was labeled in matching Blackletter. For example, a section for Sunday, April 22, has the following texts in matching blackletter: "Sunday, April 22, 1923", "The New York Times Rotogravure Picture Section 5 In Two Parts".

Other newspapers that use apparently identical faces for their mastheads are The Des Moines Register and The Charlotte Observer, which uses a modified version. The Chronicle Journal of Thunder Bay, Ottawa, is somewhat similar, and may be used as a basis for the "J". But the I in The Seattle Intelligencer's nameplate is almost identical to the "J" in the Chronicle's! The Naples (Florida) Daily News' nameplate is similar to the original (1860's) NY Times nameplate.

A book, "The Paper", about the New York Times, used NY Times-style blackletter for its title. The P has been incorporated into my version of the full font - still a work in progress. There are small differences between the "a" in "Paper" and the "a"s in "Magazine". There's a significant difference between the "p" and the "p" as seen in the Style magazine's "The Talk".

On February 21, 1967, the logo masthead was changed. Significant changes were made to the T, k, and s, and to the M, a, and z from "Magazine", and a period after "The New York Times" was eliminated.

Summary: The following characters can be authentically represented by having appeared in The New York Times or affiliated publications:

Upper Case
D, H, M, N, P, R, S, T, Y
Multiple varieties of some of these.

Lower Case
All but k and q.
Multiple varieties of some letters.

OTHER INFORMATION
The New York Times running text font, called Imperial, used to be set at 8.5 point on
8.8 point. They changed (9/18/94) to setting it at 8.7 point on 9.6 point
to aid legibility. Imperial was designed by Edwin W. Shaar in the 1950s
and adopted by The Times in 1967. (Scott Tilden)

A December 13, 2003 facelift made the following changes:
Headlines: Cheltenham, as redesigned by Matthew Carter
Text: Imperial
Section Titles (regular sections):
Bookman Headline
Daily special sections:
Memphis
Some Sunday sections:
Franklin Gothic EF

Someone said "Engravers Old English" is the closest existing font to the NYTimes masthead. It's not even close.

From Dick Margulis:
Interesting story about the New York Time logotype. You may recall that
it included a terminal period until February 1967.
At the time they dropped it, they issued a news release asserting that this one change
would save them some large number of tons of printing ink per year. (I don't pretend to recall the number, but it was something astonishing.)
That was incidental to the reason for the change--they were trying to
spruce up the appearance a bit and made other changes as well, although
nothing so radical as their recent introduction of color to the news
sections.

(From the NY Times on-line Timeline)
December 1, 1896
Until December 1, 1896, the Times followed an older precedent by hyphenating New-York.

Tuesday, February 21, 1967
The top of the front page is redesigned. "What has God re-wrought?" asks a letter to the editor. "No period in the New York Times masthead? No tittle to your title? The weather unboxed? 'All the News' restyled?"