So far - the donor action was a stainless SPS, the barrel is a Douglas 10 twist, and the trigger is a Calvin Elite. The SPS recoil lug measured well so I used it and also used the SPS bottom metal. If it was a heavier recoiling cartridge I would probably have used a thicker lug, or if the factory lug didn't mic I would have used an aftermarket part, but the original was a good one.
It will likely be topped with a VX-3i 30mm 4.5x14 with a 40mm objective. I already have a spare HS Precision stock and a CDL stock gathering dust that I may use, or I may order an new one from Stocky's. I should have that figured out soon enough to get onto the range with it in a couple of weeks.