Luckily the rust on my blue 610 wasn't as bad as is the example from the original poster in this thread. A long Evaporust soak, some Aircraft paint remover took care of it. Now I am giving it a Rustoleum paint job so I can ride it long enough to decide if I want to get it powder coated.

It is interesting that it seems to be mostly the racing blue bikes and a lot on the top tube near brake ons. It makes me speculate that there was an issue with the flux used on the braze ons?