I replaced just the fabric on my three slide toppers, as the mechanisms were still good. If you have awnings with segmented covers at the "last wrap" to give weather protection when retracted, be sure to specify that when ordering.
Even Camping World can provide the replacement covers and will install them, but you would have to order the specific size you need as they don't stock every possible size and color combination...
2007 Tour Master T40C
Acura MDX toad
"It takes a great deal of time to recover from any improvement..."