thinking of saleing my 70 red /red/ red duster
Don't sail it. Keep the engine in it and go for it.
You be the judge.
I think your car is worth 20k, give or take. The best thing you can do is set up a good ad, regardless of where you go online and give as much info and history on the car as you can. The whole "too much to list" is a line of lazy BS. Everyone will want to know what you have there and the more people know, the more interest it will gain.