Eye relief is not the usual complaint on the PU sniper, rather its getting good check weld on the stock. There is a gentleman over on Gunboards that makes reproduction M41b sniper check rests that work very well on PU sniper stocks.

Here is a link to him, the 2nd pic shows it mounted on a PU sniper. I am not sure he still makes them but you may want to drop him a line and see.

WTS Swedish M41b Cheek rests, Made to order, New price