I picked up a Model 57 4in this weekend. What the problem is it's nickle and it's peeling. The gun looks fantastic and if you hold the gun a foot in front of you, you wouldn't be able to tell. What I need to know is, is this a factory finish, is there any way to tell by the serial number? The serial is n144000, when I take the grips off it has a Lg. N and 51915. Any input would be helpful. Thank you