and preferably fairly quickly, how would you go about it?
The local buy and sell is full of tire kickers and lowballers who don't appreciate a cleaned and serviced machine. Ebay has a lot of fraudsters and I don't know if I want to handle that sort of experience at the moment.
What about with relatively limited time to devote to it? (i.e. an hour or so each to box a machine for shipping may be unrealistic... though that may be less than the time to "host" people in the house to look at the machines and want me to teach them to sew.)
I created a bit of a space crisis by making a purchase that will be arriving in 3 weeks that I would love to finance a bit this way and want to see a bunch of these machines that I brought back to life go to good sewing homes.
I'm going to put out some emails to some vintage machine lovers around my area to let them know that some of the machines are going, but I don't expect a lot out of that.