Thanks Mike - noted. I doubt very much I'll be able to find original ammo, but excited to think I might; I would not be tempted to shoot it! Saying that I did feed over 50 rounds of 1940 .303 through my Enfield a couple of years ago; not a glitch!
Am interested as to how rim thickness can be adjusted, are you able to steer/shed any light on how this can be achieved?

Very many thanks to you and other friendly, helpful forum members.

Let he who casts the first stone - be accurate.
If he cannot be accurate, he should practice first.