I picked this watch up in a box of old watches. It is a Bulova Ambassador micro rotor. It has a 12EBACD movement with the date code of M5. The case back has the case code of M4. What makes this one interestring is that the dial reads Automatic and not Self Winding like the other Ambassadors. It is not running and is missing the outer crown stem and crown and possible a inner ring as the move is a bit loose in the case. It measures 35mm. The case back is marked Stainless Steel, Swiss, CB, 506 and M4. The back says Bulova Waterproof with a dancing female. The dial has applied Bulova and printed Ambassador, Automatic and Swiss.
On these types of cases it is critical to have the correct crystal, which helps hold the movt secure in the case. This is the Buren Micro Rotor ebauche, and it is the platform upon which the first automatic chronographs were built by a joint venture including Hamilton, Buren, Tag Heuer and Breitling.
1964 Ambassador.
