Very hard to value a car without some pictures of it. I read the words and I see the HJ Monaro on the cover of the latest Survivor Car magazine. But I could be totally wrong.
If it was like the HJ it would be worth $20000 to $30000 maybe more. It is a 4 door and not a 2 door!
But it could just as well be under $20000. It depends on condition of the paint, the trim and the engine.
I'm struggling to get my head around why a dealership would paint out all the chrome on the car to use it as a demo. This is well before blackout chrome became popular.
The LE Monaro was demo material around the same time with gold and maroon and bling.
Ken