I like to see the original rifle, thanks. Please don't replicate the barrel contours?!?! Thsoe wafer inserts are great but you may need a recoil abutment.
Again, I don't do this kind of work, but the ring placement for modern scopes (which they keep making shorter 'n shorter) is mostly (I think) determined by the location of the adjustment turret.
The basic problem is: are you trying to adapt a modern scope with internal adjustmens to a vintage rifle, or place an external adjustment scope on a modern stocked hunting rifle? A quandry in this shop?!?!
Please correct me if I'm amiss?!?!
