Originally Posted by luker

saddle would be a Brooks B-15 or maybe a Wright's. Or if you're not worried about exactness, then maybe an Ideale...
Superbe was the top of the line for suntour, and they work very well, and there is a large suntour fan club that keeps the value of all things superbe high. And they really are at least as good as anything from the period.

If the fork is 531 then the full frameset is probably 531.

Sounds a lot like a MkII. In '74 they painted the rear triangle, by '76 they had chromed the rear triangle. By '78 they had gone from Huret to Campy GS parts. At some point ('76?) they changed the name from competition to competition gs. They also migrated to a really cool fully sloping fork crown without any apparent lugs. From your description it sounds like you have an earlier one - are the decals gold or white?