After backing everything up, I deleted Normal.NewMacros1, and set up a new Normal template again. It seems to have ironed out the problems I had, and all the macros now show up in the menu.

A remaining niggle is that some keyboard shortcuts simply won't 'take', but I can assign a shortcut to the same macros on the QAT. Compared to the problems I've had before, this is a small one, and I can live with it for the time being.

Thank you, Charles and Andrew, for your help with these problems. I shall look into global templates when I have a bit more time. If I did have a Normal template on OneDrive, where would it be located? I've looked and not found anything.