I believe that is actually a Thompson Renegade.
It has steel furniture instead of brass, no patch box, and a 1" barrel instead of 15/16". I am not sure if the Renegade was ever made as a kit gun. It may have only been the Hawkins that was available as a kit.
My Hawkins I build from a kit, and my Renegade was a factory assembled gun.
The Renegades were made in .50 and .54 caliber and some were made in .56 caliber smoothbore as well (for states where rifled ML's aren't/wernt legal).
The Renegade was a "user gun"... the patchbox was removed and the furniture was made of steel to reduce cost as few who bought one simply to hunt with them during a ML season cared about such things.. I am guessing that the slightly bigger barrel was made so that the model could easily accommodate the .56 caliber smoothbore option.
FWIW, it is probably drilled and tapped to accept the T/C scope base as well.
For best accuracy on these things you want a really tight fitting ball. I am using a .495 ball with a .015 patch in the .50 caliber for instance. Be aware that I am no longer using the original factory barrel in that one. The factory barrel has shallower groves and might want a .010 patch if I recall correctly. Said tight fitting ball wont be easily rammed with the factory ramrod. An aftermarket rod is the way to go. For my .50 caliber I use a 3/8" stainless rod with a brass muzzle protector. For my .56 caliber, I simply use a 1/2" wooden dowel that I saturated the ends of with epoxy to make the ends stronger. I use a short ball starter in both cases to start the ball.
Rick