As I noted in another gallery about the scratch built/kit part originals,
take this one for example.

Now look at the side window in the body, if you lay the whole deal
on it's back and close the canopy, then take away the legs,
arms and the top frame, add skids, an extra window where the arm joins at the shoulder,
a tail and rotor blades and you might just wind up with summat like this.