Again, as a big, fat, know it all, Rickman supplied forks to Munch for awhile. 41mm tubes, if I recall correctly. And got some brakes from him for their own stuff. If your front brake has a high single scoop on the right side and Friedl's last name cast into it, the fork set and brake are likely worth as much as the rest of the bike. Nice bikes, lucky man. There's a BSA here in town with an NSU engine in it, maybe your Rickman . . . . . .