I bought it a little over four years ago from eil.com. It is from the estate of Dave Berryman, who was a huge Moody Blues fan. So, my copy is even addressed to Dave! Here is a link to Justin Hayward's website where he mentions Dave Berryman:
http://www.justinhayward.com/remember-dave-berryman/

Here is a link to an image of Hayward's signature on my record cover:
https://imgur.com/xXpsF1d

It's easily the greatest memorabilia I've ever owned.
How many people could say they had a mint copy of their favorite album, signed by the whole band (and the cover artist), and addressed to their name?! The only thing that would make it better is if I really was the one getting it signed.

I'm sure if you watched ebay you could find some of these from that estate from time to time. There were a lot of them. Most probably have "Dave" on them too though, so maybe non-Daves wouldn't be so interested.