Bruce Hansen writes: This is the Lunar Drilling Rig built from a 1962 set of the same name (8 1/2 set). The motor in this model drives a rotating drill in the base and a rotating “antenna” (everything above the Boiler). The drill/antenna rotate at about 60 RPM’s.
Gilbert’s 1962 sets all had featured models on the box tops. This was the featured model of this year’s 8 1/2 set.
The antenna is made from base plates, angle girders, C girders, turret plates, a Boiler top and a few other girders/axles/gears.