Im hoping this is the right place to post this. I have a Model 13-1 SN-d939163. I am wondering if anyone can tell me about when it was born. When I bout the gun it was a square butt and was blued. I decided the round butts fit my hand better. The bluing was begining to show its age and since I had "converted" it. I needed to refinish it. Since it is a carry/working gun. I didnt want to have it reblued. I decided to durabake it. I recently stripped it down, beadblasted it, durabaked it and added Hogue Bantam grips. I am now carrying it and it shoots like a laser. I am just now curious how old it is.