For one, the serial number seems fitting for the rifle but the wood look s awfully out of the place, and the other the wood looks decent but the serial number seems way off. Is this type of stuff typical for rebuilds?
Both of these have replacement stocks. All WW2 M1A1 stocks were Walnut. The first one is sitting in an Italian military replacement stock as it's Beech. The second one could be in a Springfield Armory replacement stock as it's Birch. Both have been through complete rebuilds.