The Thompson is far from dead, check out Bullberry Barrels. I have a Bullberry .321 Bullschuetzen that was designed by the original owner of Bullberry for the Coors bottling company for a schuetzen match they sponsored. They built 12 pistols in .321 Bullschuetzen, which is a 32-40 shortened by 3/4" and sized to .321. Its a breech loading set-up and seriously competitive at 100yds, I haven't spent nearly enough time developing the right load but feel its capable of holding an inch if I do my job.
There are other dealers out there that are supporting the older Contenders, parts are available, they are very simple to service, spring changes do wonders.