Here's an idea for you. Connect with a sewing group or guild. Offer to do a free lecture on vintage sewing machines with the understanding that these machines are for sale. Explain the various features and tell why vintage machines are better. Show the differences between the various machines. Allow people to try them. Explain what you to to recondition them. See what happens! At worst, you have lugged some machines. At best, you have a bunch of customers. Christmas is coming, and this is a good time for gift buying.
I'd be interested to know what you have for sale.
Cricket