@ handrawn

Thanks for the pointer to those menu settings.
Turns out I had "Same layers on all pages in document" ticked.
When un-ticked I can toggle the eye-ball on one page and the others stay put.

@ Acorn

Erm, I hear what you say, but I'll have to get back to you if I try out your suggested method.
For now, "handrawn" has nailed it.