Sorry Nigel, I read it but very shallowly, my fault.
Thats OK. This is a more complicated upgrade than usual. Now that you have reached the admin pages if you look at Modules > Manage modules you will find many are not enabled. I recommend you enable all of them for now. That will get everything working.
Then you can set up your menus as you want them, and your new “widget bar”. Once they all work you can choose to disable some modules if you wish – but it is not necessary.