I may be a bit off base on this but it's my understanding that the rifles that shot a bit better that the rest during testing at the factory were set aside for possible conversion and were marked with the TR on the left side of the butt socket. They were again test fired at H&H and those that met the requirements there were then converted the sniper configuration. Not all with the TR marking went on to become No.4T's, although I've yet to see one it's possible to run across a standard No.4 with the TR marking. Just because the rifle your looking to buy is most new does'nt mean it will shoot any better than one several thousand rounds down the tube. I also agree with JM, if it's made it this long in that condition theres no use in ruining it now by making a repro T out of it.