I never met Rex, but I did own one of his barrels many years past. Back in the '70s & '80s it was pretty common to see his barrels, along with a Haddaway lock, on rifles made in KY. I remember that he made his lands wider than his grooves in the belief that more surface bearing on the patched ball controlled it better. There was an article in Muzzle Blasts about him some years back. I ran into a couple of his barrels (unmarked) at a ML shop in Las Vegas in the early '90s (Ray's Beaver Bag). They were readily recognizable by the rifling.
Roger B.