You might try listing it on AutoTrader.com or even on eBay Motors. Those listings will be seen by many more people than those who look at your local paper. Because it is a collectible classic car, some buyers may be willing to travel distances to buy that vehicle.
You might also try putting a for sale sign on it and parking it on a highly traveled street or shopping center. If any local businesses will allow you to post signs in their windows, you could try that. I don't know what city you live in, but www.craigslist.org has a list of cities and states where you can list anything for sale, including cars.