Mount is a LaRue LT-158. It has 10 MOA cant and places the optic 1.44" above the rail. The LT-158 can be had in 1", 30 mm, 34 mm, or 35 mm sizes. I find both the cant and height to be just about perfect for the Covert. Obviously, that mount would be quite tall for most bolt guns, but it works pretty on a flat top rail system like the DTA has, and 10 MOA is more than enough cant for the distances I typically shoot.
The buttstock cover w cheekpad came from Brian Muoio, who had a business called "Tactical Textile". I did a search but couldn't find his webpage anymore, so I don't know if he is still making them. I had him make two, actually. One is the one pictured above with the cheekpad; the other is simply a buttstock pad without the cheekpad. That is the one I usually use. You can see a picture of both on p. 51 of this thread, about 2/3 way down the page.