Oh, yes, the photo has been published before!

The British press, especially Hello!,  Daily Mail,  and The Times, have gone a bit crazy over recently found photo albums that once belonged to the Duke of Windsor.

http://www.dailymail.co.uk/femail/article-2966575/Resplendent-royal-robes-French-exile-Duke-Windsor-poses-garden-country-retreat-shared-Wallis-Simpson-abdication-never-seen-photograph.html

The Mail claims that the photograph of the Duke of Windsor, dressed in his Garter robe, posing for a photograph in his garden, has never been published.

I say Bull Merdé!    The photo was one of a series taken in 1953 by James Gunn.  This particular photo was included in Philip Ziegler's official biography, King Edward VIII,  published in 1990.

from Hugo Vicker's book, The Private World of the Duke and Duchess of Windsor

From Philip Ziegler's  King Edward VIII