frank spencer wrote:
I have a toilet pan which is just over a year old and is showing
streaks running down from the outlet holes around the rim. Presumably
this is some sort of limescale residue but this did not appear on the
previous pan over a period of many years. The supplier says that as it
is over a year old it is out of waranty but surely it should last
longer than that? and to try cleaning it with a pumice stone, any other
advise or suggestions please?

Do not try cleaning it with a pumice stone (IMO).
First try a descaling gel of some form.