I just got some of that Pellon P45 at JoAnn Fabrics yesterday. 20" wide and it's one a 48 yard role and like $1.20 a yard or something. I just bought a 10 yard length to try out on a couple older planes that need some recoverage. It, and other products , were on sale at a %50 off so it was $6.95 or something for 10 yards.
Haven't tried to use it just yet, but maybe soon if I can get my butt in gear again.