Bill i rush to explain.
The hull in the area is 4mm thick and has been reinforced with the strips of styrene. All is set with CA glue. Inside the "cavity" as You can see i have wedged / glued drilled washer made out of brass to stop the nut spining when i tighten the bolt. Underneath i placed the 1,5 cm steel washer between the model and the steel support tube - same as between the wood and steel tube.
Besides it is only "works bench" for when the work is caried out. For final presentation i have purchased brass knobs ( below ) to give it looks and strength.
TBC...