Larry;
Thanks for the info. I was pretty sure the article I had read on it was in Shooting Sportsman , but was thinking an earlier gun. The fact it had passed post 54 proof does lend some credence to the idea he thought he was OK.
I do know though that "I" would know better than to shoot a shell in such a gun having a fired length which allowed the shell end to actually lap into the gun's bore. Thus if I had done this I would still consider it an act of Foolishness, every one else will just have to decide for themselves as to how it applies to them.
I am doubly surprised that WR would have cut such a chamber at that late a date, & that the proof house would have passed it as they would have obviously been well aware the common British shell would exceed the actual chamber length.