You've got a dandy rifle there. The serial number dates from fall of 1943 (I'm going from memory here), probably October. It's been rebarreled with a September of 1953 Springfield Armory barrel. The trigger housing is of World War II Winchester manufacture.
The parts numbers on the various parts have revision suffixes on them that can tell a tale. If I had more time I could look them up
If the rifle could talk it might have a tale to tell. It very likely served in some capacity in World War II and could have served in Korea, being rebuilt both in between the two conflicts and afterward. It could have also seen a lot of stateside training duties. It could have been a part of a foreign aid package to any of a host of nations.
Sure would like to see a couple of photos of the complete rifle.