1951 21 j 10bm model. The only crystal to fit is a CMY 312-6 for an Academy Award Model. The case is all 10k gold filled. The date, case, 21j movement and crystal all suggest it may be an academy, we know there are plain dial varients around. I can find no adverts for this model or hardly any other models the same as. So any ideas? Excellency or Academy are the two front runners at present!
I only show the AA "YY" as taking the GS CMY312-18 crystal which is 24.2 X 22.8mm in the 1952 catalog.
I do show a CMY312-6 in the 1966 catalog fitting a AA, no variant listed, and it is a smaller crystal, 24.0 x 22.7mm
I would go with a tentative AA, but not the "YY"
That's interesting because I have a feeling that the 312-18 may just fit too, although I haven't got one to try. I know that fits the Brewster model also. I wonder if they used the same crystal then decided to amend it at a later date? Just a thought as I know gs liked to have different numbers for some crystals although these would be near enough the same and fit the same models...guess it gave them more money with watchmakers buying more inventory?