@sdetweil Progress, thank you. After purging and removing those files, I ran the install script. It completes, but during the npm install step I notice:
E: Unable to correct problems, you have held broken packages.
node: /lib/arm-linux-gnueabihf/libstdc++.so.6: version `GLIBCXX_3.4.26' not found (required by node)
The script completes (but doesn’t give a npm version number, interestingly). I rebooted the pi and the mirror doesn’t start and pm2 command is not found.