Mine came from Texas with verry little rust other than just a little in the cab corners wich I replaced but the rest was solid and clean so I didn't remove the cab due to time restraints and having a body man willing to take it on RIGHT NOW pushed me A BUNCH! as allot of folks here have posted, gettin into a body shop and gettin paint done can be a FOREVER process so I jumped on the chance ot get my AD in the shop and get the paint goin.
But I wish I would have had the time to pull the cab just to get in all the nookes an crannies and give it a good once over since I was that far into it.
But I'm pretty confident I got the offending rust taken care of with the cab on.
Basically it all boils down to what ya want to do and how far you want to go.
Tim