Scott Duff's red book has one in the 1.269 range which should be about the same.

Lots going on in this range to switch things over but it could be a GHD (possibly even a large box which are really tough though I have seen several sell loose), probably a long pinion but it could have been short, with either grooved or checkered knobs, could have some A marked parts and/or some CM, rear handguard should have no clearance cut and should have a grooved clip, front sight seal should still be intact but you are getting close to that ending.

This is a really interesting era as there was so much going on, but I would recomend getting Scott's red book - it is worth every penny and is the best for this kind of info. And if you call the number at the link (below the pic) Scott will usually be the one who actually picks up the phone ... (grin);



Scott Duff Publications Historic Martial Arms: M1 Garand, M1 Carbine, M1903, Krag, M1911A1