A TC Hawken? For $50??? If has no visible bulges, original blue, and no signs of abuse, it's probably safe to shoot. First make sure it's not loaded by shoving the ramrod down and measuring how far it goes.
TC. Get some fresh powder, ram a ball down over 70 grains of 2F powder, tie it off to an old tire and then step back about 10 yards and set it off with a lanyard from behind a tree. If it holds together, you're probably okay.
I am not a gunsmith, but I have been shooting a .54 TC Hawken since 1984. You probably could get a gunsmith to look at it for less than it'll cost to send it back.
If what you're looking for is a deer rifle, you may want to think about buying a Green Mountain IBC barrel for it in 1-in-28" . It'll shoot conicals a lot better than the original TC barrel that was meant more for round ball.
$50 is a great buy. I'd double your money sight unseen just for the parts.