Thanks Leon. Here's a little more information for any who care. I found the original Mack from which this fake was copied (a Herpolsheimer graded SGC 30) and show the two side by side. Note the light wrinkling or spider creases in the lower left quadrant of the photo, which extend into the border:
There also are a couple of other tells when the cards are compared closely. Note the oversized borders and slightly larger size of the fake, although it is within specs.
While the toning of the two Macks is noticeably different, the fake is not far off from other real Herpolsheimers. Here I've added a common from that set that actually measures very closely to the Mack, despite my inability to get the scan to scale.
As you can see, the "yellowing" is not far off, although the borders on the fake look a little "dirty" or less sharp.
My point is that these are getting tougher to distinguish--they are not your grandfather's reprints. They apparently do not cost much to make. Allow for further improvements and factor that commons might be added with scarcer backs and it makes for potential problems on the horizon for whoever might think of adding m101s to their collection. Please proceed with caution.