Well I was being a bit stupid.......maybe.
When you get to the page where it asks about the equipment, I was trying to set the number of devices against the list.
What you have to do it set the correct number against the item - in my case "DSC VHF" "1" THEN click ADD against that line which moves the item into a box at the top of the page, and it is what gets moved into that box that gets authorised / licensed.
Simples when you know how, although when I last tried it the "Add" button didn't seem to do anything.
Spoke to a very nice helpful chap at Ofcom - straight through, no long queues- , and suggested that a few "help" boxes on the new web pages might help numpties like me.
So now have license for "Lunasea" and MMSI No. Cool.