I agree that 66-67s do not seem to be as popular as 68-70 - I prefer the 66-67s though, and have seen seemingly nice ones advertised in the low teens. If I found one for 10K that need no body work / paint, I'd be sorely tempted.
The poly probably hurts this one a little bit. If the rust were bad in the quarters that would put me off as well. Nice interior, though.