I've met Galen at a few shows over the years, and have heard the stories since then.
I dunno anything about those, partly because I've never been fortunate enough to have a car where documentation would have been an issue.
I've only been able to get known, "one of a gazillion" vehicles that are also either known not to be numbers matching, or even if they were, being Numbers matching or not wouldn't make a whole 50¢ difference in what I could possibly get for any of them.... never a 6 pack or 340 or hemi among them..... lessee.... a 85/6 D150... that I swapped engines in, myself....current /6 is a 74 with a 77 head....
A Durango with 300k+ on it.... a rotted out 96 Dakota.... a "low line" 78 fury 2 door hardtop with a 318.... and more, over the years .. none worth losing sleep over "originality" on...