Sketch of the FlatHOMEKitchen Area
This picture shows the end of an era, of The Avengers in the sixties, because it is the "destroyed" studio set of 3 Stable Mews, which was John Steed’s home from 1966 - 1969.

The production of Requiem was completed on 13th February.1969, so this has to be the last scene in Steed’s flat, because Steed's flat did not appear in the last episode, Bizarre (3rd March 69) and there is only a short scene in Tara’s flat in Take-Over (completed on 23rd April.1969).
Destroyed flat in Requiem Destroyed flat in Requiem Destroyed flat in Requiem Destroyed flat in Requiem
Steed lent his flat twice to Mother, in Noon Doomsday and in here in Requiem.

There was twice a damage at the glass elements of the door, the first time when Mrs. Peel throw a vase through the panel (where was her key?) in The Joker after Steed felt down the stairs, the second damage was caused by a bullet in Get-A-Way!
The flat took also some damage, when a bomb exploded in the living room in episode Something Nasty in the Nursery and a window broke, when Tara threw her shoe through it to warn Steed.
The cybernaut crashed the entrance door in series 5 episode The Return of the Cybernauts.
John Steed's Flats - No.4
Damage and Destruction