Sat there and studied a pic of an authentic Mantle compared to this one and I can't help but feel that this is a fake. I looked at the two printings that Topps came out with and immediately ruled out one. The one I studied was the "missing pixel" version of the card, where the corner of the black border is missing a pixel, thus creating an angle where the point should be. This card either has a less severe angle or is completely rounded.
Authentic...
http://goodwinandco.com/ItemImages/0...52-10a_lg.jpeg
Mantle in question...
http://www.ebay.com/itm/161957962758...%3AMEBIDX%3AIT