I have a almost identical one a couple thousand serial # above yours. I lettered mine and found it was shipped in 6 1/2". I would have bet my house it was original untill I got that letter! I seen another identical to mine that was about 7 #s different. Yours doesnt have the red insert? I thought all were suppose to have them. I have the original cokes, but here is a picture of mine with a pair of presentation grips I put on. You definetly need to letter that gun!