I'm nearly 70 percent sure it is. I have a pre-print and the same letter. The signature is 100 identical with the one on this picture, though I received one from Phantom of the Opera (sent the letter to London address)
Congrats on getting a response! I did not get anything yet from the B&G filming location. I did get a Phantom photo from the London address so at least he has changed the photo. I think they're all preprints.
tuttiefruittie