I know this guys style better than i know my own hand writing. I don't know Clapton's actual signature but I know that 9 and 5. Check the date. Also note the John Lennon face/signature. That's the only example i have to hand. I know its his effort.
He is sloppy, look the way he spelled Jimi. When I pointed it out, he chopped the top off and put it in another auction. The painting sold for £15,000.