I've got a 158 Topper made in 1972, modern stocks will fit it, although the forend hanger is a little different. Some older models had a snap on forend also.
I think the barrel fitting back then didn't have as close a tolerance as they do now, even tho they aren't precise now, they're a lot closer. The 1972 Topper barrel underlug is a good .100" longer than a modern underlug, but others have old model barrels that fit fine on late frames.
Tim