OK, thanks guys. Will keep your ideas in mind.

When I say the walls need skimming it is not because the plaster is
terrible but the house is a 1930's construction and after removing the
paper the walls have large areas of size that are firmly attached and
trying to remove them just gouges the plaster. Suppose I could try
polycell basecoat or similar rather than skimming? Just at the
investigation stage.