I was cleaning my PM7 after an IDPA match when I noticed the elevation adjustment gear/screw on the top of the rear sight was split in half! The screw head is half missing! The rear sight looks like a Bo-Mar, but it says DW. Has anyone ever seen this before? Can this adjustment screw be replaced? I kind of hope I can get a replacement part and DIY and not have to send the slide or pistol in for a repair.