This is an interesting survivor. I thought it was a goner but got it running in spite of the obvious water damage and I just love the "patina" on the dial and hands. Clearly a 1961 Bulova 23 but I cannot find a match to the dial and case in the line books.
The stainless steel mono case has beveled lugs and a notched bezel ring that secures the compression fit crystal. The date code is M1. The dial has all triangle hour markers and has quadrant lines on the dial. I can find the dial in a different case but not both case and dial. Probably one of the many undocumented variants as everything looks original. The movement is a 23J 10BZAC. I could not find a date code on the movement.
In reply to Do I see "M1" on the… by neetstuf-4-u