I spent some good, quality time with the canopy frame today, getting it to fit perfectly and slide pretty well.
First, I finished attaching the center slide rail with the assistance of my friend Steve.
Next, in accordance with the drawings, I bent the aft part of canopy frame to give the proper clearance from the aft slide rail. After about 20 iterations of removing the frame, bending it against my workbench, and reinstalling it on the plane, I was able to get the clearance to within the prescribed 5/8" to 3/4". Mine is 11/16".
Finally, I filed the center slide block in several locations to eliminate some of the sharp edges I think are making it bind slightly on the rail. After the filing (and spraying it with a bit of LPS-1), it slides a bit better. I'll continue to work on it next time.