I think sears stopped selling those in the late 70's, bout' the time T/C became popular. I know the pistols got a bad rap for poor quality and inaccuracy, but they where very in-expensive.
and believe the 15/16 TC hawken barrel will fit
Maybe, the key areas for fit will be,,
How the breech fit's over the lock plate and alienment with the hammer, that can usually be filed to fit and the hammer bent just a bit. The breech plug hook is easy too fit.
The position of the wedgekey underlug on the barrel. Up/down or vertical adjustment is easy, but the horizontal location needs to be in place to avoid larger modifications. The front rail might be too long or short but that's easy to cut.
I guess the only way to find out is to find a t/c barrel and try it. There all over the place, find a local gunsmith or pawnshop, if they don't have one maybe they know someone who does.
