Tez,
You are a genius!
So far, no problems apart from a briefly dropped connection late last night.
I note that the computer seems to need a minute or two to find the connection at bootup, which may explain why it kept reverting to the 169.x.x.x address, but all seems to be well at last. Will let you know if it doesn't last, but next time you are near Potters Bar, the first drink is on me!
Many thanks
of Hertfordshire