First thing, after re-reading your original posting and the problem described in it, I can't see why you've ended up with the valveblock in pieces. If this is a 1969 V8 250, it should be a slim bumper car, and I thought by then they had moved to the PRND21 selector pattern. That later pattern should have the governor line plate, the early PRND2D1L pattern should have a D2-D1 valve instead of the plate. The screws holding the valve block together just have spring washers. They just need to be torqued up. The converter check valve is the ball and spring, and as far as I remember from the last time I looked in the early book, it moved position from where it's shown in the illustrations. I wouldn't expect the gearbox to be original even though it's a matching numbers car. The box is 48 years old, and they fail, a lot.