Here's a link to some Vito serial # charts. http://doctorsax.biz/vito_ser_nos.htm Yanigasawa produced a lot of its B6 baritones, stencilled for sale under other brands, between 1967 and 1989. They are highly regarded horns. The Yanigasawa serial number convention up until the early 1980s had either the second and third or third and fourth digits indicating the year of manufacture. That convention appears to have been followed for the Vito Japan horns made by Yanigasawa.