The set for the engine room of the DS9 USS Defiant was built at the end of season 3 as a permanent set. In later seasons the engine room was seen increasingly less, and I wonder when it was last seen / when the set was torn down.
At the end of DS9 Season 5, the Defiant-class engineering set was deemed to be taking up much-wanted room in the swing set area of the Paramount sound stages used by Star Trek: Deep Space Nine. This resulted in the set for an overhead flying rig – originally built and used for Season 2 installment "Melora" – to be removed from that stage.
I'm not sure if the latter quote means that the engine room set was removed, or that just the overhead flying rig was removed. The engine room appears in season 6 episode 14 'One Little Ship', so that seems to indicate that the quote above was just about the overhead flying rig. Or did they rebuild the set just for that season 6 episode? (Note: I haven't watched DS9 s7 yet)
Anyway, my question: when was the Defiant engine room set last seen?