Not sure how it happened but I ended up with two iterations of my FedWiki at DigitalOcean. I had started one, and was using the IP to point to it. Then I set up a subdomain at DreamHost and pointed that subdomain at the IP. When I followed the subdomain address swf.mcmorgan.org, it started a second wiki.
Another possible culprit is that I renamed the droplet on DigitalOcean to make it clearer what the droplet was running.
In either case, I now had two wikis seemingly sharing the same IP. Ok, that might only mean that they are in the same farm. They might not collide - which was my concern. The first one used the IP for the address in pages and in the footer. The second one, the one that started up when I came at it using the sfw.mcmorgan.org subdomain used that subdomain address in the footer. The first one had to go.
I restarted the wiki at DigitalOcean. (The console works better in Safari than Chrome.) Still two wikis. I forced a restart of the server. Still two. I considered destroying the droplet and restarting from scratch, but thought that might create even more problems. I decided to move the content from the IP addressed wiki to the subdomain addressed wiki, and sort of mothball the first.
Along the way, I located Ward's notes on how to save the wiki content.
Your pages are yours and you should have them safely saved and backed up on your own computers. This is easy to do. Just grab the export and keep it safe.
I exported and save the json file, but couldn't figure out how to restore from it. It looks like it requires a script, so I did it by hand. There wasn't a lot of content to move and I wanted a fresh start.
Update 8 Jun 2015. The way to move wiki files is to SFTP to the instance and move the files in .wiki directory.