I decided to fabricate the center canopy slide today. It's made of a piece of aluminum bar stock riveted to another piece of aluminum that is 1" wide and about 1/16" thick. Sounds easy and it isn't to difficult but it did take considerable time to layout and drill all the required holes (rivet holes, screw hols for mounting the fuselage, and lightening holes). The rivets that attach the two pieces are double flush riveted. That is, you countersink both sides of the assembly so you get flush heads on both sides of the slide.
My current problem is I can't find a measurement for the fore and aft positioning of the slide on the top centerline of the fuselage. Need to do some research before match drilling and attaching the slide.