Thanks, Sebastian, but it still doesn't move them to the Common Settings section of the control bar. I even double checked by comparing the Tabs table in the database between a default site and the one I am re-constructing to ensure they are exactly the same. The only difference I could see (apart from the Guid's etc.) is that the default had the CreatedByUserID set to -1 in the default site, and mine had 1. So I changed mine to -1 and it still made no difference. I even copied and pasted (just to be sure) the page name from the default site Tabs table to mine for example, LogViewer, and it made no difference.

Are you sure there is not some other/additional mechanism that controls it?

DNN came out with a new version 8.0.3 today. In addition to the security fix, two other good things happened:

1. The update succeeded with no errors, not even errors on the admin updates to 8.0.3
2. All the Admin default menu items are now arranged properly in the right places!

 So, I'm going to mark this 'solved'.