I have an 03 that was redone by RI in 1944. They added a scope base(hinges where bolt release is at), and has a peep sight. Has your rifle been reconditioned? It should be stamped if it was. I believe the valuable ones are the ones that have not been reconditioned. I would not alter one that had not been reconditioned. I believe all the CMP rifles have been redone, therefore collector value is not high. If you want to alter a recon., I do not think you would hurt it too much. I have one right now with a scope mount from RI that I would sell for $300. Tom.