The Westfalia SO42 was offered by Volkswagen from 1965-1967 with just under 13k made during the entire 3 year production. Options included 4 different models (A42/B42/C42/D42) as well as units delivered directly in Europe which would be designated with no port or Westy code (but a Westfalia 523xxx paint code).
Westfalia SO42 Registry
This is a registry for all Volkswagen Westfalia SO42's, made between 1965 - 1967. When you enter your SO42, please include as much detail as you can including photos inside/out as well as photos of the mcode plate and fabrik-nr. plate. You can obscure part of the VIN if you don't want that listed in the registry but that field is not public anyways.