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.
I have several of these 11AAC watches with Duo Wind dials. I recently got five or six NOS Balance Completes for them., so if you need one, let me know by P.M. The movements are one of the most sophisticated and difficult to work on movements I have yet encountered. If anyone would like to have theirs serviced, I would be glad to go through it at a reasonable price. Just P.M. me.
I recently got mine running great and will post the results in due course. It was a challange since they are complicated movements with lots of additional springs and wheels - very different from the 10AUC. Both of mine are dated 1950 (LO). I believe the 11AAC was the first Duo Wind technology, and came before the 10AUC, which was later replaced by the 10BRC and later still the 10CSC and CMC movements. 1948 date stamp on the automatic rotor weight makes it possibly the ealiest automatic. I'm just updating this post so as to say I doubt the idea that the 11AAC was a prototype since I have three...but it was likely the first Duo Wind movement, preceeding the 10AUC. Rob