1973 Duster

Here is my suggestions:
1. Spend a few hours, and a few bucks, and get it running. It will be far more attractive to ANY potential buyer if they know it runs. A decent tune up does not cost that much.
2. Clean and detail it. It does not have to be perfect, but a degrease, wash, polish, vacuum, tire shine works wonders.
3. List it confidently. /6 = MPG, and everyone is interested in that right now. List the Good and Bad, but do not dwell on the bad. The car is 35 years old. People expect some rust. Focus on the positive....Nice interior, new tires, whatever. Let them determine if the positives outweigh the negatives.
4. List it on Craigslist. Ebay, and forums are nice, but they are nationwide. Craigslist is free, and someone local can come and inspect it.
5. List your price, with a buffer for negotiation. Do not reveal what you have in it. Listing what you have is like showing your hand, then betting in Poker. Unless your competition is blind, you lose.