Deville Convt. worth?

[Auror_AH]

I am looking to purchase a 1970 Deville Convt. I was told by the owner it was just under a 3 if he were using a scale of 1-6 I can't seem to find online any book value web sites that go back as far as 1970 anyone know of any websites that may help me. Or even any rough guesses as to what it may be worth.
Needs:
Intake Manifold
Brake work
New Wipers
A couple other things I am overlooking at the moment

[NHpatriot]

Originally Posted by Auror_AH

I am looking to purchase a 1970 Deville Convt. I was told by the owner it was just under a 3 if he were using a scale of 1-6 I can't seem to find online any book value web sites that go back as far as 1970 anyone know of any websites that may help me. Or even any rough guesses as to what it may be worth.
Needs:
Intake Manifold
Brake work
New Wipers
A couple other things I am overlooking at the moment

I recently bought a 69 Devill convt. it passed inspection. There's very little rust but the engine has a collapsed lifter and at least one bad connecting rod bearing. I think I'll pull the motor over the winter and rebuild it. I paid $2500 for it.
It has various small electrical problems but I'm an electronic engineer so I'm not worried about fixing them. (the carpenters house is never finished and the masons chimmney isn't done).