Genesis of the Daleks - S12-E4
Visible crew/equipment: Just after The Daleks move past the Doctor and the female Thal soldier in the corridor, a piece of lighting equipment is reflected on the wall behind her. (00:08:00)
Genesis of the Daleks - S12-E4
Visible crew/equipment: In episode 1, when General Ravon is being held at gunpoint and he says 'they won't last much longer', the shadow of the boom pole is moving on the door behind him. (00:15:15)
Revenge of the Cybermen - S12-E5
Visible crew/equipment: Quite a few times during this story arc you can see Vogans without their gold eye make-up so you can see human coloured eyelids when the rest of them is all brown.
Answer: It was never destroyed on-screen; it was intact at the end of the TV movie, and destroyed by the start of the 2005 series. It was destroyed in the novel "The Ancestor Cell," but in a completely different manner to what happened in the series.
DaveJB