No one ever made custom actions for the TCR, but barrels were made in about anything you wanted. For a while several aftermarket companies also got into the barrel game. After talking with several, once interest died down they stopped seeing a big enough profit and discontinued offering barrels. I asked thompson center about having a company CNC the mono blocks and got the following response:
"unfortunately we no longer have any parts for the TCR. We understand why you would go to another company for parts in order to keep your firearm operable; however we will not honor any warranty once aftermarket parts are installed. If a TCR is presented to us for repair; we appraise and offer a replacement with a different model line."
So bottom line, if your 87 ever dies you would probably get a new encore as a replacement. As for barrels you can still find them and the chase is part of the draw for me. Unlike an encore where you can walk into any dick and jane gunshop and see new barrels on the shelf.