These curtain tracks fit up inside the valences on my 1990 GB 32, but I suspect they will fit many other models. I have tried to attach a photo but just in case, each track is 5/8" wide, 1/4" high, U-shaped, with little 1/4" lips, making the opening about 1/4" wide. They are designed to work with those tiny little plastic sliders sewn into the tops of the pleated window curtains. The photo also shows the stopper screw at the end of each track.
47 1/2" (two)
Price is $10 each, plus UPS shipping inside USA
Contact Mike Bennett at mbennett (at) astrosociety.org or call/text to 408-446-5297.