In the Guild ward of Sigil its a 12 story building
Take the wood lift up to the 5th floor and you will find.
Mrs Willymott's excelanet Exterminator Agency.
Think 1920s NY sheek and your just about there, but for the imps doing paper work.
The rooms seem larger than they should be, so there is some Dimension manipulation going on.
The Agency is owned by,
Mrs Willymott is a 18 foot tall 'Gold Devil' {yes there is gossip about that, some believe she is half gold Dragon, Half greater Devil, but no one has ever lived to tell if that is true.} who likes to wear high fashion very much in the Devil in this case wears prada.
She never talks about who Mr Willymott may be, but the gossip in the office is, he was the 1st infestation she got rid off.
Her personal assistant is a cross dressing Tiefling Call Just Boddy Who hands out your assignments. And takes great pleasure in giving your team the really C**y ones no other team wants.