I guessed at the year based on movement model. Wondering about this case, did Bulova produce salesmans display watches, or is this possibly a marriage? Case diameter about 33mm, case back appears to be base metal or similar composition, with acrylic crystal. Movement has small 48 marking on winding rotor, and either BXW or 8XW on balance bridge. Only markings I can find.
In reply to There ya go, 11 AAC and 48 on by bobbee
It potentially being an early 48 model would make sense to have a saleman see-thru back case. I can just see the salesman rocking up to a jeweler, watch in hand showing how the movement works. without the need to take the back off.
I love these clear backs and wish all mechanicals had them. I'm forever showing of mine to friends and family and hate having to dissemble when I do it.
48 Duo Wind gets my vote. (tentative of course)
The F410, 415 (sweep sec) Bidynator dates to 1942, just for background info. This doesn't mean Bulova used it immediately, obviously, but it was around. The patent wasn't granted to Felsa until the following year, 1943, but was filed and pending prior to that. Quite a few watches in the 40's took advantage of this well made new movt.