I have an early Renegade .54, before they started marking the barrel to say Renegade, and no warning label, etc. It does have some odd markings on it ... can't remember what they are off hand, and I don't know who made the barrel. I tried to find out a while back, never could get a concrete answer through all the searching I did.
Its in the back of the safe, at some point I'll pull it out and take it down to see what the markings are again. I'll keep an eye on this thread, maybe some solid info will come. Maybe you'll get something from TC semi, but my gut says its a long shot.