Helping a friend out and I bought what appears to be an M1 Garand. Its all GI except for the receiver. Its devoid of any markings. It just has a serial # and that it was made by CAI in St. Albans VT. And just says M1 rifle 30-06. Barrel and most other parts are Springfield and it shoots fine. There are no arsenal marks on the stock. Also no importer marks I guess because it was never sold to another country? Anyone have any ideas?