@jsabine cheers! They are screw holes - so as big as a rawl plug diameter. There are quite a few of them. Previous people had those silly toothbrush holders and shelves everywhere. I might try some silicone, see how it looks and can always revisit. Cheers
andos
How big are the holes? If they're just where fixing screws have been removed, silicone.
Obviously it's a bodge, but it works and is surprisingly discreet.