> Is this US product [Kroil], in UK terms, WD40, does anyone know?

Hello Nigel.  Kroil is definitely _not_ WD40!  WD40 contains some oil,
but is mostly solvent, and its lubricating properties dissipate rather
rapidly.

I've repaired clocks, and one of the things I hate to see is a "repair"
that has been done by soaking a clockwork in WD40 -- it hardens into
a glaze or coating that is very difficult to remove.  Kroil, when its
solvent evaporates, leaves behind a very thin oil which acts as a
lubricant, but doesn't form a glaze like whatever is in WD40.

WD40, as its name (Water Displacing formula number 40) implies, has
only one good use, and that is displacing water on a mechanism that has
become wet.  After the water is gone, the item should be rinsed with
something like denatured alcohol or acetone, dried, and then lubricated
properly.

Bob Loesch