Originally Posted by
Slightspeed
I'm really confused by the Raleigh serial numbers. I built up an alley find frame into what I think is a 1973 Super Course. The problem is that I can't find any reference to the serial number I have. It has the Capella lugs, which should make it a 531 frame. The reference sites all talk about letter prefix, and all I have is numbers, similar to yours.
Super Courses were always made of 531 straight gauge tubing in the main triangle. I do have to ask if you are certain that you don't have a Carlton model. They were made in the same facility, and share a lot of common features with Raleighs.