1903a4 scope mount shims

I bought a few 1903a4 scope mount shims from Numrich years ago and was wondering if these are reproductions, not that it would make the gun not original(possibly). My thought is, should they be curved to match the chamber bridge before they are put on or be flat as sold.

They are soft metal, I took each one, put it in place under the mount and pressed a 1 inch socket over it——-done

As I recall, the scope base shims started out flat when new.

J.B.