I've seen a couple examples of this. Looks to be a 50th Wedding Anniversary gift. Pretty cool... Still unknown. Unusual engraved lugs on a round watch. Either redialed at some time and the Bulova was left off.. or maybe she purchased it that way for him. Numbers and hands match the other unknown examples.
Plaines
Didn't we attack this one last month? This one has 21j 10AK, triangle date symbol = 1945

I don't think we ever figured it out did we?
I have a pair of these 49 and 51...my 51 dial has outer minute track and open 10 seconds hash marks for the secs track like yours Plains, perhaps the Bulova was cleaned off accidentaly as the dial looks the same...17jewel 10BM
May 1950 ad.
The "WINDSOR".

Windsor
Windsor from me. I think the lugs are the same in ad and watch.
"WINDSOR"
The 21 Jeweled version displayed within the thread appears to be a frankie as the Dial does not quite fit the Case.
Windsor