FoolsSulphur, sorry I failed to read your post in the entire before responding (I plead sleep depravation : that's my story and i'm sticking to it.)
I too wanted a .62 smoothie for my renegade, and things started out as a stock which I picked up at a gun show for a fantastic price, considering how much figure is in the wood, but the bad news... it was for a 15/16 barrel, and my Thompson Center is a Renegade with the one inch channel ... oh, well ... begin work with chisel and sandpaper and let the good times roll ...
A few trips to FleaBay later, I had collected a new percussion .54 barrel, and a percussion lock, and a sewerpipe .54 (both barrels are one inch, and both were breached )... the good barrel I put to one side, as well as the lock, and I sent the rusty barrel to Mr. Hoyt to be turned into a .62 smoothie. He did a wonderful job, and I felt a bit guilty pulling the breech plug out. What I really wanted was a .62 smoothie in flint.
Now the tricky bit: I got the correct size "flint" breech plug from Track of the Wolf (I would recommend that you call them first and be sure you get the right plug) ... the timing of the plug is the hard part.
Usually, you have to make the breech face bottom out on the barrel and one of the flats meet up at the same time. Since you haven't yet cut the barrel for sights, lugs and so on, it doesn't really matter which flat comes into line, so long as they line up and you don't have the breech plug over torqued (or worse yet, too loose). But in this build, the flat had to be the right one, so that the hook in the breech plug, the under lugs, sights, and all that good stuff all came together in one happy unit.
Perhaps the ML spirit was smiling upon me, but I was able to get this accomplished in about a Saturday, and with a bare minimum of swearing and skinned knuckles. By way of disclaimer, I attribute this to nothing other than plain old dumb luck, and in no way am I trying to imply that I have any skill or expertise in this area (with the exception of the swearing, at which I excel).
So, it can be done, but your results may vary.
You mentioned that your loaner T/C was right handed. If I deduce that you're left handed, your options narrow pretty rapidly. The only left hand T/C Renegade stock I can locate is on Gun Broker, and the owner wants $350 bucks for it which, considering that it's a very plain piece of word, is highway robbery in my opinion. You might want to call dick Greensides at Pecatonica and see if he can get you squared away - he's an excellent fellow, great stocks and really good prices.
As regards Lyman products, I have never heard anything bad about them, and I wouldn't hesitate to own one; it's just that all my factory made ML gear comes from the now [pretty much] defunct Thompson Center. They were much nicer before Smith & Wesson bought them out.
Hope this helps, or at least provides some insight. Good luck with your project!