Somewhere I had said the weakness of this gun is the amount of inletting necessary weakens the stock and limits the amount the upper receiver tang can be tightened without the screw interfering with the safety. Too much redundant stress is placed on metal to wood points, points unable to handle it. I plan to do the plywood insert. I will inlet where the screw attaches to the upper tang about 1/4 inch. I will place a steel washer in that hole. I will fabricate a new screw to attach the tang. As the tang needs to be tightened I will insert washers. Since the screw holding the upper tang also attached to the trigger guard tang, I will be screwing a metal strip the length of the trigger guard tang to the surface of the plywood insert. I will tap that strip so as to use machine screws to hold the trigger tang to the metal strip. This will allow me to tighten the stock by removing the trigger guard and the metal strip. Thus stress will be removed from the trigger guard tang and the travel of the safety will no longer be affected by the screw going into the upper tang.
If there is any interest here in this procedure, say so and I will take pictures as I go along
