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 two tone
very desirable rly 30's first prototype 8 3/4" hunter, rare find in pink gold and ss, full watchmaker instruction movement, 3 pieces case, beautiful raise gold marker dial, orig pink gold bi g crown, clean movement, running strong.