I was at Wal-Mart looking at muzzle loading stuff they have on clearance they have a couple of different Thompson / Center universalscope mount rings & bases there. 1 was the see-thru set most people don't like them & the other was a standard mount. They were on sale for $15.
I know most of Wal- Mart stuff is junk but these have T/C name on them & said American made I would think they should be alright.