its a lot of money for an rs turbo in the first place.
being an rs turbo over 20 years old its probably had more panels/paint/repairs than any cat d write off car would ever need anyway!

regardless though,the stigma of cat d/c will always affect a cars value,so i would say it would be worth a third less than a similar condition/spec car.

i would look around for what else is on offer for that sort of money.