The Back Cover of The Sorcerer's Lady
The Library of Chatsworth House
You cannot see to well through the scanned images but note:-
The portrait before the door in each picture (Henry VIII btw)
The Bookcases flanking the door
The balcony railings above the door
The position of the desks
The busts in each picture
The pattern of the arms of the couches shaped into an "S"
I think there is a definite resemblance here - what about you?