Brownells should carry most anything you would need. First time I have ever heard of one of those breaking. I would look up a local gunsmith and see what he says, short of that I would speak with the folks at the Springfield, MO Bass pro shop, or Cabela's close to you for direction to the 'smith you need. Return to Remington is an option but that must be done by an FFL holder because the part you need replaced is connected to the receiver which carries the serial number. Pawn and gun shops have one of these and for a nominal fee, which changes from shop to shop. When returning to Remington, or to anyone for that matter, the barrel isn't needed, making shipping that much easier. Good luck with it, keep us posted.
Creativity is just intelligence fooling around