Seaforth72/RobD:
I neglected to post the picture of the S51 H&H conversion mark on the butt. The bolt is stamped with the full OC3695 serial number - it was hard to show the full number in the photo. The forearm also is stamped with the OC3695 serial. All the components including the magazine are properly "S" marked. I found the re-numbered scope can interesting. It adds confirmation that the original scope remained with the rifle. The can contains a 1961 dated bag of desiccant and the cleaning cloth although the adjustment tool is missing. I am not surprised that the original can was replaced between 1942 and 1961.
I have no idea what the purpose of the two screws in the back-sight are for -I assume some sort of repair. I thought someone on the board might have an answer.