Agreed. On top is a legitimate '56 Mantle graded by PSA (not my card) the old way with the number next to the description of condition. Below it is the OP's card.
I'm certainly no expert, so I present this only for everyone's edification, but among the glaring differences on the flips are:
1. Square corners on the white portion vs. rounded corners.
2. Completely different UPC (?) code look, feel, size and positioning.
3. Different typefaces/weight throughout.
4. Type is much too close to the border on one side and much too far away from it on the other.
5. Type is spaced differently from the borders on top and bottom.
6. Different typeface/size for "PSA."
56mantle.jpg