I did a digital overlay of the mystery man and several of the Verdi's. Much better match than similar test with Longfellow (but only one photo, so not statistically significant).

But all that may means is that mystery man looks a bit like Verdi.

The chances are vanishingly small that it is an actual famous person. A search on ebay for "antique photographs" yields 354 pages of results. Many of these have the description NUDE FRENCH BIG BUTT, but many seem to be similar style and vintage.

Still a great find and a fun mystery.