have seen more than one - at least two in the u pull its in the last decade - but the yard managements were too crush happy! idiots, if you ask me imho.
I have seen a few rust free but most are slant 6 models & have rust in rear quarters at least !
I live in texas & you would think most cars would be rust free But in reality they rust here just like everywhere else .. But most all have good frame rails here !
I like all the brands but Mopar is by far the hardest to find in virgin metal !
If you start w/ as a rust free 70-71 Duster it will save you a ton of money & time to complete for sure !