As she related to me, she
The photograph was autographed. She removed the photo from the frame to see if it was a printed photo and it wasn't. It was on photo stock, and the autograph was in blue grease pencil. Neither of us is a handwriting expert, but after looking at various samples of Thatcher's signature on the Internet, we both concluded that the signature was indeed that of the British Iron Lady. Jinny reframed the photo and I found a very nice spot for it.
It certainly not that hard to buy autographed photos of Baroness Thatcher, but I doubt very seriously that I'll ever come across one for $10, which is what Jinny paid for mine. As the old saying goes, "One man's junk is another man's treasure," and my Margaret Thatcher photo is a treasure indeed.