okay, a little more progress. The noise is coming from the driveshaft (hub end, not gearbox end)

Does anyone know why this would be, its not a grinding noise, just a squeak! I can live with most things
but pulling up to a junction and pulling away with what sounds like an old creaking door being opened isn't
one of lifes pleasures!

Its not the rubber gaiter that is squeaking, it sounds more like the other side of the gaiter
(where the shaft goes into the hub)