thanks everybody for the advice
I took a chance and bought the gorilla glue gel.....scuffed up the leather and the plastic real good, and made sure both surfaces were clean and free of any leather debris, dirt, and wiped the plastic with some rubbing alcohol to clean it.......i applied the glue around the perimeter of the plastic case, made an "x" of glue in the middle, then spread it around with a Q-tip.......when I stuck the plastic to the leather it was already beginning to set.....looks like this solved the issue, but i suppose only time will tell..