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
original 1st series bb, c burcherer's
this is the dream of all bb collector, an all original double name tropica dial retailed by c burcherer in swiss, 1st series model is very hard to find in good original condition, what a find.