I think that part is urethane, I'd definately strip it mechanically by sanding or media blasting-don't use any chemical stripper. Clean with waterborne wax and grease remover-don't use any solvent based cleaners. Do your repairs, how big are the repairs? tears? gouges? When the repairs are done scuff the whole thing down with a scotchbrite/water/scuffing paste or Ajax and rinse really well then clean with waterborne w&g remover, shoot two coats of epoxy primer and let it set for a few days-then sand and reprime as needed. SPI epoxy works very well on these flexible parts-best IMO. For repair material on the bare plastic SEM, 3M, Fusor, Kent all make some good plastic repair products. There's also flexible polyester glaze that works well over the epoxy primer for cosmetic repairs.