The fuel store appeared in Bringers Of Wonder part 2. The large red door, with the yellow sign "Atomic Fuel Store" above, matches the full-sized studio set. There is also a large numeral "4" alongside the door.
This building was used in Bringers Of Wonder as the atomic fuel store. The red door is painted on; close up you can see it is not actually a door (it was probably one of the anonymous Alpha buildings redressed for this episode).
Later in the episode we see another shot, with a small moonbuggy in front. The building is an entirely different model, a larger scale.
After the episode, the larger model was repainted in green, and more detailing was added to the top. It appeared in the Gerry Anderson "Alien Attack" Jif commercial, on top of the hill over the launch silos. The yellow "fuel store" sign and the numeral "4" were not altered. Originally the model had a rear side, but this has been lost. Screenshot thanks to Wayne Oates
Contents copyright Martin Willey. Thanks to Wayne Oates and Jim Winch