Originally Posted by rimrock

Thanks for the link, I did not know about this site. It is missing a lot of information (e.g. the 4000 Superbe front brakes are not listed), it looks like a work in progress. But I guess late 70's is probably when I bought the brakes, based on the info there. Mine are definitely earlier than the pair of 4700's pictured, they have a fatter nut, and someone else commented the same thing.