The original was a wired UtechSmart gaming mouse. I checked Amazon and it was no longer available.
I spent half an hour searching Amazon for something else, and finally settled on a wired TITANWOLF gaming mouse.
It arrived yesterday. It's identical to the UtechSmart one except with a different logo and a gloss finish rather than a matt one. Even the software is the same. Oh, also the cable is red (which is good as it makes it easier to follow it) but slightly shorter (which is not good as it gives me less play when I need to move my PC unit around).
I had to configure the buttons so that the 11 and 12 produced - and = to match what MMO skill bars want. Gawd knows why the defaults are NUM+ and NUM- on a gaming mouse, but they are.
I also sped it up, so my wife can't use it and so will be reluctant to commandeer my PC.
The UtechSmart mouse is now available on Amazon again. It's £2.03 more than the TITANWOLF one, so I don't feel cheated.
Hmm, it looks as if I need a new mouse mat, too.