All you needed was a wall with three feet of empty space behind it!
Or the back of the set could stick into another room I guess (if you need me I'll be in the Bathroom checking tubes).
These had to be installed in a space that was designed from the start to accommodate them.
Has anyone been watching Mad Men? Don Drapers' Manhattan Apartment has a built in set, no doubt just a prop.
It's a Color set but the Screen shape says B&W.