Curvex style mens watch, Black dial, possiblh guilt, signed 'Bulova', 7AH movement, 21 jewel, Possible gold filled case
I think you have a 1936 President. I am currently trying to see if there is an ad with the black dial. I am sure there probably was. Plain case like this one but a different dial. Presidents are 21 jewel and the white dial is like your black one.

This is the engraved case but it shows they did a black dial for the President. Ad Nov 26, 1937, Oakland, Ca.

Not finding an ad with the black dial but I feel comfortable voting for it being a President.
1936 Bulova President
Agreed, 21 jewelled would certainly put it in the Bulova President category and the ad you posted above does indicate balck dial as an option.
1936 Bulova President
1936 Bulova President
Good ad finds, Kathy
1936 Bulova President
Got My Vote too, 36 President
Does the addition of the samll seconds onthe dial effect the designation at all?