The small Ordnance wheel is found on WW2 rifles after about mid 1943. Not sure when it was no longer used. Canfield states the meaning of the stamping is the subject of some debate. Some believe it is a "factory stock sub-inspectors mark". As to the MW mark, I have never seen that but don't believe it is a rebuild mark, at least not U.S. The HR and date under the butt plate is interesting, I have never seen that either but sure seems as it was stamped by H&R. How about a picture of that marking.