Hi Jbloom, the cartouches on the left wrist are the US Ordnance Department crossed cannon insignia, FJA was Frank J Atwood, Inspector or arms in the district where Remington was located, the RA stands for Remington Arms. If the barrel date is within a month or two of August '43 you most likely hav an original barrel. You will most likely have a circled 'P' just aft of the trigger guard which is the firing proof.