The first thing that came to mind was a desktop publishing business from your home. You could do that almost entirely through email if you set it up that way, and you could drum up business through flyers and ads and over the internet. Of course a new business takes a long time to get profitable, but it could work.

I was a desktop publishing specialist for a large corporation and could have used your prepress experience in that job. I worked with the print shop a lot.
You have a lot of good skills and many ways to go.