Thanks Ray. To the best of my knowledge all of the Trials rifles were converted at Enfield during 1941 (??possibly into 1942 as well??), & I doubt very much if any of them had body wall T's when first converted. However, in line with the instructions to mark all sniper's rifles with the T, they would have been marked after the event, but as I mentioned above, this only seemed to happen in practice some of the time. Does that help?

Cheers.