FWIW, most gunsmiths won't drill and tap an H&R 12ga for a scope rail, H&R won't either, they solder them on. I suspect a smith wouldn't do two holes for a peep site either, I only drilled one hole for the WGRS peep on mine, and it's blind hole, used Loctite 380 to stick it in place to avoid the second hole, the chamber wall is just a bit too thin for multiple holes, specially all the way thru, IMO
Tim