I know that MoD didn't have receivers as replacement parts and when the receiver was worn out it was done. The Canadianicon system had replacement receivers dated up to 1956 as far as I know. The Long Branch C No.4Mk.1 with the Maltby receiver is a mystery as it hasn't seen allot of use and all that's been changed is the receiver with the original serial number ground and the 92L, ( I goofed before as it's a 92L not 95L rifle), serial number stamped in it's place. I also have a LB 1956 dated receiver stamped 77Lxxxx which was 1944 original production serial range I think. Interesting rifles. Wish they could talk.