That it sold for only $550 should tell you all you need to know. Real ones go for 15 grand and up. Looks nothing like the few dozen he signed when the album came out. COA's from Christoper Morales and American Royal Arts hurt the credibility even more.
Well, there are actually several interesting things here: 1. There are few copies of "Double Fantasy" signed by Lennon. 2. Lennon's signature from that period doesn't match the one you're showing.
3. This signature style reminds me a lot of the forger nicknamed "SoCal"; the style of the "nn" is unmistakable.