The final two elements I felt necessary to complete my model was this secondary rotor that I’d noticed on a few of my references, and the hill on which the whole thing stood.
As with several other previously discussed assets in this scene, the second rotor and the hill are made out of manipulated polygon primitives, with the former being cubes and pipes, and the latter coming from a cube.
Seeing the everything placed on top of the hill made me quite happy as it made it seem so complete.