I'm thinking of selling off one of my Glocks. A mod. 21 that, according to the list of serial numbers, is one of the first 21's ever made. It has the prefix of UB but the serial number is on the high side of 500, so I doubt it is really early; but it IS in that group of the first run of 21's. The finish is well worn on the edges and on the flats it is thinning. Lots of holster wear. (See Pic) When I received it, it still had plain fixed sights and the heavy trigger plastic spring thing in it, so I ordered all new innards and topped it off with a set of Tru-Glo tritium/fiber optic night sights. I, of course, saved all the parts that were replaced. My question to the forum is this: Is there any additional value to the gun based on the earliness of its manufacture? Does a first run model have any extra value over and above that of just another used Glock 21? As I recall, the anticipation of Glock finally releasing a large caliber gun was very high. And as expected, police depts. were lined up to get theirs. But now that they are commonplace, I wonder about collect-ability.