So I was out at the flea market today and there was a lady ( about 45 years old ) who had a photo album full of signed photographs and index cards.  I didn't notice most of the signatures but ended up picking up a few because they were all priced at 20 dollars or less.   I got a Yogi Berra, which oddly enough was authenticated by JSA, it had the little sticker on it.  I got a Tony Perez, Alan Page, Dooley Womack, Clete Boyer, and a few others.  Most of these were under 10 dollars which is a decent deal.  Then I got to his and immediately recognized the signature of Paul McCartney.  However, I don't know enough about his autograph to determine an authentic or a fake.  She didn't even know who the card was signed by and sold it to me for 3 dollars o,O

I just casually asked her how much she wanted for it, and she looked at the signature and said, ummmm.....ummmm......who is that signed by?  I kinda acted dumbfounded.  The question is, did I throw 3 dollars in the trash or is this real?  She said her son use to live in NY and collected autograph by mail and in person.  I figured for 3 dollars it was worth a shot.  I know ZERO about Beetles autographs.  HELP ANYONE?