looked like a dry day so decided to stick my replacement bung in the rear of the headlamp unit, the original went walkabout at my previous Ford Garage , Took a while but I got one all the way from Australia courtesy of Crispymk2 and in return I did him a favour of which he will post a piccy of sometime soon.
I did it without taking the headlamp out, undid the coolant retainer bolt and lifted it out of the way, ensure you pinch the hose with your fingers so that you don't slice it when getting it passed one of the engine mounts, same on return, also just pull the hose off one of the other hose joiners that keeps it all tidy.
As can be seen from the picture I used my huge technical knowledge and skills to do this job . The seal bung went in very easy, return all the parts and job done.

Pleased its sorted steve

At last!