Are you saying it's known that the sample dates from the 20's or 30's ... or just that it looks that way to you?
The closest that comes to mind is Florentine Bold (predigitally). Today's digital, commercial version of Florentine does not include the bold. Opti offered the bold, but they are long out of business - and were of shady reputation anyway.
Oddly enough, the Solotype Catalog's brief showing of Florentine Bold (probably phototype) includes an 'A' much like yours - something I've not seen in any other showing of the typeface.
Tapered strokes like this were found in some 1920s lettering designs. The most famous is the poster lettering for Fritz Lang's Metropolis


See also Andreas Stötzner's font Grund

Captured from commoncrawl.org on 21 Apr 2015. original URL