Selling old auto parts making a web site or selling outright?

I'd start with finding people who want to buy the who lot, unless you enjoy the "hands-on" work and dealing with the thousands of assholes who comprise the retail public. There are also sellers on eBay and Craigslist whom you could mimic, not to mention advertising in Hemmings and other specialty rags.

One thought, maybe worth a try:

https://www.history.com/shows/american-pickers

It's TV but they are real people. Follow the links.

How is anyone going to find your website without you putting advertising $$ in to get the word out there?

you could try doing both or putting an ad in the paper

do both