Thank you gary baldy,
Shame some of you peeps on here don't read what others actually post.
I come from London, and the saying 'north of Watford' is and has been used by many, many people. The fact that it probably comes from Watford Gap originally, is not the saying that most Londoners use. After all, we know that over time, sayings and phrases get abbreviated and corrupted. Reading the whole part of the link I posted, gives the whole perspective on the issue. There still is contention as to the origin, hence DeNiro's ref from the OED (I looked this up also). So, although I admit to sometimes being a "muppet", I don't care for your reference in this case, as if what I have said is in any way wrong or that I am deluded.