I have a RI/3 marked grip with the small crossed cannons on the bottom on my M1A1icon.
Came from the CMPicon that way. NO proof P on the stock. The early second run M1A1's were like that.
The first second run guns had a mix of both high and low wood stock and early and late grips. It was a little while into the second run that they moved the crossed cannon to the side. The second run guns did not have the proof P from the factory. Inland discontinued that on their stocks during the period there were not making M1A1s in late '43 early '44