I found the following information in the Glock Serial Number thread. "1993, G19 Upgrade Glock Model 19, 9mm Luger caliber, requires an upgrade for all pistols. These pistols have the potential for an UNINTENTIONAL DISCHARGE of a cartridge with the action open. The Glock Model 19 pistol slide has a bottom protrusion, whose function is to push cartridges from the top of the magazine into the chamber. When the pistol is jammed in a double feed situation, the slide protrusion can come in contact with the primer of the jammed cartridge and cause UNINTENTIONAL DISCHARGE while the action is open." I recently purchased an older Glock 19 made in 1992 (AAV prefix). I haven't seen the pistol yet except pictures of the exterior. I was wondering if it does need the upgrade what is involved? Will the slide need to be replaced or is there an easier fix? I don't want to send it to Glock and end up with mismatched serial numbers or worse yet a Gen 3 frame. I specifically bought it because I prefer the Gen 2 frames without finger grooves. Thanks for your help.