Hello guys. I just brought the gun out of my safe and carefully removed the grips again to look for a factory rework code. The only mark I see on the left side of the inside grip frame is a small letter F. That's the only mark I see. My other question I forgot to ask before is what do the numbers stand for that are marked on the cylinder crane and the inside of the frame....normally this is the location where colt revolvers are marked with their serial numbers. Both sets of these numbers match. Thanks again for the help and merry christmas.