Sorry Bill, should have got back to you soooooooner but have been jetting along to finish the Meteor.
You is correct my lad, join the top wing first, get it in the correct position, aligned correctly and make sure it is well secured. Then you can start the rigging.
As I mentioned in my thread, as long as you have plenty of wire to play with, attach your loopy thing (buckle) and get it set in its hole with glue. Again I cheated and use Zap Kickset to speed the setting up. When set, gently pull the loose end of the thread through the loop and the shim, shifting the shim up the connected wire as you go. When you have no more loose thread to pull through, tuck it in as close as you can to the attached part of the thread and pull the shim into place , but again gently while keeping tension on the thread. A dab of glue and when set, snip of the surplus thread.
Hope this helps.