Help with a '73 Cutlass 455 w/ factory Hurst

I'm trying get the relative value on my father-in-laws 1973 Cutlass
Supreme that he wants to sell. I hope someone on this message board
will lend their expertise. He bought the car new and will never have
the time to restore it. The Olds been garaged for the last 20 years
and hasn't been started in the last 8 so its dirty and needs a quite a
bit of cleaning up. There is some surface rust by the driver's door
and floor panel but I don't think too much. It has no dents or dings
in the body and has never been in an accident.
Here's the details:

Everything on the car is factory

1973 Olds Cutlass Supreme
White on Cranberry (white Landau top, white vinyl interior, Cranberry
paint)
Bucket seats
Olds body colored mags
455 Rocket V8
Hurst 4 Speed (factory option)
Factory Dual Exhaust
Power Steering/Brakes
33,256 miles on the odometer

The car was special ordered in '73 and is not a 442 or Hurst Olds but
has most of the performance options.

I would appreciate any insight.
Thanks,
Dan
Please remove the word "spam" from my email address to contact me.