Please help with the history of this rifle. It is stamped under the bolt handle: Enfield 1911 Sht L.E. Stamped under the safety: P (large) 410 (crossed out) RFI 1942 The rear handgard has a half-circle cut out of it on the top of the barrel where it joins the receiver and what looks like a poorly stamped "P" stamped on the barrel (although it could be an "F".) On the right side of the butt stock is a circle with ISA with an arrow over, stamped in the circle. There are numerous stampings under the forestock that are not legible except for a KA over a B with a line between. There is a U on the bolt head. It doesn't say No.1 Mk III but I assume that is what it is, made in the Enfield in 1911 and refurbished in 1942. The crossed out 410 suggests to me that it may have served as a 410 shotgun before being rebarreled in 1942. Am I guessing anything correctly so far? What does the P on the barrel and butt stock socket mean, and what do the letters RFI stand for? How about the U on the boly head?