I have a set not mint from a '73 Westy. Reasonable condition I'll have to get them out of shed tomorrow and get some photos.
you would need to remove the early style runners from drivers side and replace with later type. Passenger side would need them welding in. Later bays have the same runners. I have some late bay seats im not in a hurry to part with but are very good. Id be looking at 500 for the pair with runners so 400 for a mint set that would go straight in might not be a bad deal.