this section is mainly focus on the develpoment of bb movement from the 30's. there are 3 series of movement being 1)8 3/4 with watchmaker intruction 2) autor rotor 3) perpetual.
examples in the picture is a full watchmarker instruction 8 3/4" prototype movement
1st series bb, double name
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.