In the clue today, the Historian here says:

“This is preservation in a different context and it's a very unusual form of preservation, but I think at the time, it was just considered to be emphasising the Britishness of the building; and making it stand out as a destination shop”

Take a guess in the comments section below. Watch Thursday, live on Back|Story, when the person with the correct guess will be announced after this week's installment of The Revealer.