Gunter,
It's your gun and your decision, but Walter Grass replaced all three bushings in a Dural framed drilling for me, when we were rebuilding it in his shop( in Germany).They were typical bushings with a flange(you called it T shaped)threaded, but not with as fine a thread as you mentioned.They were made "square" and then cut and finished to the proper angle, after being screwed in. The centers of the primers were marked and the holes for the firing pins were drilled, using a fixture he made to align the drill on both ends(so it started at the correct location at the rear and come out at the center of the primer. The fixture looked like an "E", with a screw in the middle leg, through which the drill ran. The drill was held in alignment by a hole in the rear leg.A hole in the front leg was centered over the mark for the primer center.The whole thing was dimensioned to fit around the action, between the front and middle legs. When he built a new O/U he had to bend the tang up to reach the top firing pin and bend it back later. I would guess the EL is in the bottom barrel of your gun, so you shouldn't have this problem.Good luck.BTY you can make a bottoming tap by carefully grinding the end off a plug tap.
Mike
Last edited by Der Ami; 06/10/14 06:50 PM.
