I completed the foot-well having elected to cut out an 8" diameter hole in its topside to facilitate passenger ingress. Meanwhile back at the top end there is a use for these sockets that are more normally used to fix poles in wardrobes. They also help locate our own poles during assembly in the field, whilst bolstering rigidity to some extent.
You might be wondering why I've chose to fix the rotorhead in position rather than have it rise into place with rotors turning prior boarding? Well at full scale that will be a flyer, the aircraft poised for lift-off and me racing to board under fire in my fatigues, looking very much like Robert de Niro in the Deer Hunter.
The mannekin though will race nowhere on fibreglass legs and if the vehicle won't fly with him anyway, we've more serious issues than whether the rotorhead is sliding to spec.
Top tip: orient the sockets as shown so the rivets don't catch the tubing inside.