1759 would appear to be Goudy Old Style with a bit o' squooshing.

I faked the signature a bit with Bickham, and some clever photoshopping (Feather-photocopy) and then redrew it in illustrator.

Could the Guinness be Goudy as well?

Guiness looks like a Century of some kind; perhaps a manipulated Century Schoolbook, which has more heft and less contrast than the rest of the family.

(Those SSs look awfully Times-like, though.)

I suspected that it might be Century something. Thanks Marcox!

This is what I needed it for:

A birthday invitation.
edit: kerned, thanks Stephen

Kern the Copperplate 'AY'.

erp... Thanks Stephen.

Hey, that's pretty cool. It's not a 100% match, but I think it's close enough that people will get it! Looks like it's going to be a beer bash of a birthday.

Maybe raise the apostrophe so its dot is above the N's serif and its tail curves around the serif and hangs below. Then you can kern the S and it won't be quite so detached.

How about some vertical skew on the Bickham Script to match the originals signature?

Gretchen's lucky to have a friend like you. :-)

That's very kind Linda, Thank you. She definitely enjoyed it!

What font did you end up using for the Guinness...?

I tweaked ITC Century Book Condensed. It's not the exact font Guinness used, but it was close enough for me.