Tuff Wheel Repair

I just received a used Tuff wheel that I bought online. Price was apparently a little too good to be true. While the foam doesn't have any cracks and the metal is in pretty good shape, the foam on the upper portion is not adhered to the steel core in the arc between the top two spokes. It's all in one piece but when you grab the wheel in that area you can rotate the foam around the core, forwards and back. The lower part seems to be bonded well. Anyone run into this before and come up with a fix? I have a couple thoughts but am looking for BTDT. My original thought was to try my hand at stitching a leather cover over the foam, so the repair doesn't have to look perfect, but I have to get it bonded back to the core.