There's a very good-looking 61cm Bob Jackson from the mid-1970s for sale at the classifieds on the serotta.com forum:
http://www.serotta.com/
You have to sign-up to see the pics, but they're worth the trouble. I'm biased because I ride a Bob Jackson from the same era, though the paint job on mine is in pretty bad condition compared to this one.
Mark Barnes
Astoria, Oregon USA