There’s this one, which is distributed by Whittaker in the US, I believe:
http://www.barnard.co.nz/barnard-tikka-trigger
I called Whittaker and they checked and it does install on a T1x and at the time they could get them. Maybe a couple of years ago.
No idea on reliability or quality. I was going to get a tikka but got a Kidd instead. Semi-auto better for prairie dogs and the like, haha!