you could try taking it to a custom shop to see if they can fix it, but as far as OEM replacements there is none i know of. you could check local junk yards to see if there are any in better shape than yours, but i doubt it.
welcome to the forum! what year riv do you have?
1996 with 254k miles, L32 4" FWI -> ported N* -> Ported Gen V w/3.0" Pulley, Stage 3 Phenolic I/C, ZZP FMHE, 1.84 RR, Headers and 3" pipe to mufflers, F-body brakes, and lowered on Eibachs. -RIP
AMG C400 White on black -daily