I reciently had the opportunity to examine one of the nicest original type 1 m1a1 paratrooper carbines I have ever seen. 1942 vintage and righter than rain except for one thing. The early type 1 slide had all the correct characteristics of style and finish but did not have the circled "P" stamped on it anywhere. Could it be possible that the rifle could of been assembled with an unmarked slide ?