1957 Bulova Unknown, 17J 8AC movement with a very unusual date code...L2 factory stamped and L7 hand stamped, so I don't know what was going on there. It has a 10K RGP bezel and caseback that is stamped L7. The case measures 21.3mm wide and 36.9mm lug to lug.
The Black Diamond Dial (Diamonds tested real) has raised Gold markers and Gold Dauphine hands, a new GS crystal has been installed and it has been fitted with a nice Gold & Black expansion band.
I have seen this model pictured here, but its not in the database under unknown or known models, so its in the forms someplace.
Very nice looking and running watch, might have to wear it a few times this year...