Koflach plastic boot Repair

The rand at the toe of my Koflach double plastic boot has delaminated and torn. What is the best way to fix it? I live in China so sending the boot to a cobbler in the states would cost more than they are worth.
thanks

I'd find barge cement then glue it back on and throw a layer of bike inner tube on top of that??? Or find a cobbler that can do the same.