Thanks to all the help here, I'm using Navcore 9.051 but only 875.3671 version of the UK map. I see that there are a couple of map versions which give extra features (IQ and House Numbering) - 3612 and 3696. I can't find a UK version of that number but there are Western Europe versions.
I was wondering whether there is a difference (other than size of file) in the quality of the map between the two map packs?
Unless of course there is a better version that I am unaware of??
As always, thanks for any and all help. This really is a truly helpful place.