Ring 2 Stroke Motors in Cambridgeshire, I'll have to get a number for you but they are a Saab specialist and they have LOADS of old cars so I suspect they might be interested in buying it.

However as its just rear damage I'd personally break it up and sell it on the bay, guaranteed to make more than £500, infact you might even double your money.

As someone else said it did look like a nice car, glad nothing more was injured than your pride