basically auto rotor with flat back, earlier sub second and the later sweep second, this piece is solid yellow gold case top, ss back, not gold filled, only exist in specific model 3693, 3696, 3725. this one with smooth bezel is 3696, orig arabic double dial, flat back, autor rotor, very mint case!!!
this alex clark retailed 1st series bb is differeent in all aspect, it has smaller 3 pieces case, scientific alike dial, full watchmaker instruction movement, oversize barrel crown, all original, very hard to come by.
this is an all original first automatic watch by rolex, it is so different from the later model, it has a full watchmaker instruction movement, big barrel crown, 3 pieces case, this is a historic piece, do not miss!!!
this is a very pretty all original larger bb with 35mm diameter without counting the crown, the dial is a sunken type, very clean and all original bb, runs well and keeping good time, come with an original rivited band.