There already is a pretty huge demand for your product, as Ebay has proven. You obviously also know how to deal with shipping and the other stuff since you've been doing it with ebay. Yes, if you do it right you should succeed with this, but don't expect it to happen overnight. It'll take a couple years for you to build this to a reasonably producing level.
The amount of traffic, though it's important, isn't as important as the conversion rate.
I hope Tubby chimes in on this thread, he's the expert in dealing with classic automotive stuff.
I don't know if you've ever heard of the
automotive shows at the fairgrounds in Carlisle, PA, USA (it's HUGE, draws folks from 20 states or so, and is in its 33rd year.) but you might want to look into that if you haven't. It's a natural place for you to advertise. If you exhibit there I think you get a linkback.
Good luck.