I bought a 3 window canvas replacement from the Bus Depot about a year ago
for my 76. I was VERY pleased with it and the guys there were really
helpful.  There was a mixup at first, but everyone helped to resolve it
quickly and professionally.  Plan on about 6 hours of work with 2 people,
including the removal of the old one and lots of time laying on your back
with your head down in the low end of the poptop, it gets HOT up there... I
wasn't able to salvage my old one, took a box cutter to it, but it was
pretty far gone to begin with.