You can see that nicely from the first of those pictures, where we've turned one of the edges through ninety degrees with the tube-connectors secured, and slid it into place. Note that the other side awaits the same treatment.
The only reason for attaching lengths in opposing pairs in this way is that the central section is bolted in position. Releasing these bolts allows for sufficient flex to apply the tube-connectors one by one, if this alternative method makes you any happier.
This done however we can park the airframe upright and bang in those extra rivets with the assistance of G-clamps. I have put a perimeter squeeze of silicone along the edges of the foam insert prior to capping the centre-section off and this final pressure will likely squeeze some out from around the edges.
All that remains to do now is to draw-file its rough edges and finish with a little emery cloth and the assembly is ready for a white undercoat and a shiny finish in Post Office red prior to an appearance on Instagram.
