Frank Elliot at WHMc Guns in Humboldt.
He's worked on a Mossberg for me in the past.
He has a seperate phone number than Walter's shop. It's
important that you talk to him directly (Frank) to find out what he will and won't work on.
I can't find Frank's # right now, but I'll get it if you want.
I tried one of the add on beads that had a couple of set screws to keep it on the rib. It held tight and was really bright, but I never could get my point of aim right with it. Seems like I remember it shot about a foot high at 30 yards. I would up going back to a factory white bead.