I went to one of those u pull type junk yards in my area on the off chance of finding a rigid spare tire cover. As luck would have it I came across a black Suziki Grand Vitara cover. It's 27 inch diameter is a pretty good fit for my 26 inch spare. Since the vinyl was quite torn and the shell was cracked in 2 places the yard let me have it for free.
After some internal epoxy and glass rework, sanding, and heat gun to remove the decals it was looking pretty good. A simple paint
job, added edge trim, and bonding my old vinyl to the inside I was ready to go!
It's not perfect but I still like it better than what I had.