I've had a good look underneath, under the bonnet and around the engine and located this as the problem;


Looking forward from the driver's side of the engine you can see blue coolant on the rubber nipple. The metal pipe in front of the nipple is dry as is the large hose so it seems the rubber nipple has perished. It's not a gusher just a single drop every ten seconds or so.
So two requests;
Could someone advise where I can get a eplacement rubber nipple?
Anyone near Northampton who would be willing to help with a coolant change in exchange for a few beers or advise of a garage that can?
Thanks in anticipation.