Bulova 1966 Clipper "A"
I am pretty confident this is a Clipper "A", all good and keeping time but appears to have a replaced crown. Caseback marked M6. Face Marked SelfWinding just as the ad in the database that I have included and is referenced here:
I think I can clear up the question of "Selfwinding" vs "Automatic" for this model, or maybe just make it muddier. In last photo above, note the two watches (both in my collection) are identical except for the date stamp, notation on face and serial number. Watch I am presenting to the database here is on left and an M6, the watch on right is M8. The watch previously documented is a 1967 Clipper with "automatic" on the face, but 1967 ad says self winding on face. That apparently puts the transition from selfwinding to automatic mid year 1967, and any discrepancy in ad content showing this model after mid 1967 as Selfwinding may very well be re-using old ads or drawings without an update; or using up dials in stock.