Looks to me like the frame is just fine (rust wise) from what I can see in the pics. For good used parts in the Portland/Vancouver area I like these:
http://www.dansclassic.com/index.cfm
http://www.dctrucks.net/
http://www.allamericanclassics.com/
In Olympia, you cannot beat the customer service at
http://classicheartbeat.com/