anyone have any experience replacing fibers on a fiber optic sight? broken fiber on one of the pins on my copper john sight broke about a half inch from the pin head, the rest of the fiber wraps around the circular pin guard inside a sheath and not sure if it can be pulled out and replaced. I'm way too cheap to run out and buy a new sight because of a broken fiber if I don't have to. all the web sites and mags I've looked at sell new sights but they're silent on parts and pieces. appreciate some advice