Friends, I’m going to change tactics and pursue @merefield 's idea of migrating my whole setup to a bigger VPS. Figuring out how to transfer my assets from the broken setup into the new working one will be a challenging piece of this activity, for sure, but I will try a few common-sense methods and start a new thread if none of them work. With thanks to all who chipped in, I think it’s safe to call this thread closed.