I'll play but with a tentative kind of answer haha.
I wouldn't buy it personally. I especially don't like that long 'C' in McCartney but that's not to say it's not authentic. If it came with provenance I could certainly accept it as a bit of a rushed genuine example.
..thank you for your views.. yes it's a genuine one, attained in person in London, Soho SQ earlier this year; there were about 7 people there. Macca wastn't particularly time pressured but he did not want to hang about and chat too much, but he signed for everyone and was polite/courteous. Have collected his signature over many years, and the quality definitely more variable now- usually does more abbreviated signatures, whether rushed or not. Not the best signature, but I'm not a seller so nice to have a signed Revolver LP