My kit came with a steel plate that fits the inside contour of the mount and the outside contour of the receiver . I should have my rifle in the next couple of weeks ,Bloody paperwork in Australiaicon!! then I can strip the stock off and see how it fits .

"I know the rifles in ww2 had thicker recievers if they were going to use the LSR."
I was under the impression they selected rifles from the production line for sniper rifles rather than building them as a specialty item .