My AC shroud has seen better days. It's still on my AC and as far as I know, it's from 1977 when my RV was made.
It had become quite weather beaten and was breaking in numerous spots and was quite brittle. Since the AC is larger than any newer models, I couldn't find any new shrouds for it. I ended up sanding the shroud (very gently), used a special primer on it, took some mesh cloth that is used with liquid rubber, covered the shroud and then covered that with liquid rubber. It put a nice new flexible layer over it and it's now nice and solid but flexible.
I had some of the mesh left over from when I replaced the roof on my RV. It was full of holes and rusted through. (Yes, it had a steel roof). I replaced all the plywood, put one layer of fiberglass over the plywood and then covered that with the liquid rubber and mesh. It doesn't have any leaks now.
I did purchase a vinyl cover for the AC but it didn't last very long. All I do now is use a cheap tarpaulin and cover the AC when the RV is stored for the winter.