These forend irons are off of two British guns. A Greener G gun that I bought for parts and a Charles Osborne that I’m currently working on. These pics are of the underside of the irons, showing where the factory “peen” marks are that were made by a shaped punch and a heavy hammer when fitting up the forend irons and then used for subsequent tightening.

Osborne
[Linked Image from i.ibb.co]

Greener
[Linked Image from i.ibb.co]