What part of the seat is damaged?
I think most people on this forum will not want to replace their original Comfortweave with TMI. If the outside vinyl is ripped or worn then you might be able to rescue a panel from a standard seat. Or, there are upholstery vendors who purport to have matching vinyl.
I plan on using the existing Comfort weave portion and just having new side panels attached. Would that work for you?
I didn't see an upholstery thread (albeit I didn't look that hard).