The only military conversions I know of were done at RSAF Enfield as the L8T. Long Branch also did conversions for DCRA service rifle shooters but I'm not aware of any 7.62 No.4T conversions as done there. That doesn't mean they don't exist though as we all know! The Enfield trials and tribulations are included in "Armourer's Perspective". There were many built up in the commercial trade using a variety of barrels. I've seen Sterling, CAL, and Belgian produced barrels installed on different rifles over the years. None of which were in No.4T configuration.