I cannot answer your questions but perhaps I can give you somethings to look at. I assume you are past the bearing and raising years and perhaps even have kids out on their own, if so, talk to them and ask about their friends who have had an OE. For those of you who do not know what OE means, Overseas Experience. We have hosted quite a few kids from NZ during their OEs and they have bought and sold vehicles here and in Canada, it isn't rocket science.
There are networks of younger folk that have or are planning on visiting and buying here. Google and YouTube are your friends for finding help in this and many other ways.
You don't need to pay a fee for this help, Uni's have a lot of kids who can help.
There are folks on this site that are doing what you are thinking of, perhaps some of them will chime in and help. A lot has to do with how you title your enquirers.
We only know one couple living in Oz who have done this and they may be able to help, if you give me an email address in a PM, I'll ask them to respond to you. Several of their extended families have done OEs and purchased vehicles here and sold here.