I have a Lee Enfield No.4 Mk.1. When I bought it, the peep hole on the rear sight looks like it was bored out big enough to almost fit a pencil through, which I think is the reason it's shooting 2 feet low at 100 yards looking through the regular sight. When I flip up the yardage and set it for 200 yards (just to see where it goes), it shoots 1 foot high at 100 yards. So I'm assuming the main peep hole is the problem. Anyone know where I can get a hold of a new rear sight, or is there something else I can do to remedy this?