72 Cutlass Club Post Car - Rare or Not?
 

So I got my hands on a 72 Cutlass S that was kept in a climate controlled storage unit for about 20 years. The body is in great condition except for a little rust on the floor. I have been told by some friends not to sell it since it is a post car. I've been told that it might be rare. Is this true? With some cars, I realize that just because it's rare doesn't always mean that it's worth a lot. The vin is 3G77H2R154529. Any info would be greatly appreciated! Thanks