Well, sort of...

Installing a back to wall bog and having to custom build the boxing in
as the easy way (buying a cabinet) doesn't fit the space. The bog and
sink will be side by side on this boxing and I'll need to provide for
potential access to the cistern and (just in case) the plumbing under
the sink.

SWMBO votes for 30 x 60 tiles, laid horizontally and instead of
sticking, screwing them onto a wooden frame with mirror screws, so
they're demounatable. That seems OK but, it seems to me that the screws
shouldn't be in direct contact with the tile, and could use something to
sleeve them to cushion the tile and stop it cracking.

So: Any bright ideas out there for what to use? The best I've come up
with so far is a cut down wall plug (and fingers crossed I get the size
of the hole right so it doesn't expand as I drive the screw in!)