Well, just goes to show you shouldn't believe everything you read on the internet

After a couple of hours trying to work out why several keys on my keyboard stopped working and following a wild goose because I thought I damaged a ribbon connector, I discovered the problem.
Seems my particular keyboard DOES need the wire links in two places.
I looked carefully at the traces on the pcb, and discovered two places where the solder pads for the wire links were attached to traces on the board.
I soldered in some links, and hey presto, it works again.
I'm not angry, but I'm putting this here to warn others that, while it probably doesn't matter on the majority of keyboards, it certainly did on mine.