I just drilled the screw holes on my TPS 20 MOA 1 pc base slightly oversized to fit the 8x40 screw diameter. The TPS base fit the 8x40 screw head size, so no problem there. Simple deal, took maybe 2 minutes and it buttoned up perfectly. Most any local dealers can provide the 8x40 remington screws.
BTW, with close to 2 hundred rounds down the tube, I can say the gun shoots amazing (like all my remington's - I've been very lucky with them), with several less than 1" groups at 300 m to-date. It settled on the 250 Scenars at 2850 fps, but I have had them close to 3000 fps.
Just finished preliminary load development last week so I have not had much opportunity to shoot LR yet. Soon.....