Has anyone got a sunroof switch to fit mine please?

I don't want to risk it sticking open when I'm not near home. I had to strip it again today to close it. I think there's just too much play in it.

With respect, I think your trouble is in the sunroof itself and not the switch. I have a spare set of relays etc from a sunroof which you are welcome to BORROW to check operation. I'm not far from you (at Lutterworth) so it may be worth coming to collect - or check on the spot while you are here.
Apart from very early models (1989) all sunroofs are the same, so a local scrappy may help.

Any idea where the relays are located techmanagain?

I can test the output. (If I can find them )

Relays (2) are in the roof area behind (above) the interior light panel over the windscreen. Two small square ones IIRC.
Just flick out the plastic cover over the bulbs then there are four self-tappers holding the lamp unit in, one in each corner.