Currently cleaning up & getting ready to rebuild this 1981 Centurion Pro Tour. SN M1F15682

I believe this means the bike was built in 1981 for a 1981 sale--the 1982 sale models had all switched to cantilever brakes, no? It seems like the Centurion Pro Tours existed as 3 groupings: the 1976/1977 grouping with partial chrome fork & stays, the 1978-1981 grouping with the full chrome under paint & pin-striping, and the 1982-1984 grouping with cantilevers and 'Pro Tour 15' decals.