Thanks for your reply. I have had a little progress since my last message - My problem was in using Panel Studio which I think was messing up some of your settings once I re-saved the panel and preventing the AP and Nav boxes from working properly.
I now have a panel sort of working with the instruments from ISG although to operate it in LNAV requires quite a convoluted ammount of button pushes.
Thanks again for all you help and your excellent panel - you must have worked very hard!