Hey Josh, you could be a pioneer.
Why don't you just get one made?
Find a good material, maybe contact vegetarian shoes in the UK and ask them what's the toughest material they use.
Buy some of that material.
Get a design.
Either sew one up yourself, or go to a tailor to get one made for you.
Probably have to use a leather puncturing needle. Oh, and a big pair of scissors!
If you want holes in it you can use one of those weird leather puncture tools.
If you need a hand in your quest, we could both check it out. Just PM me.