Actually, I've made one fit very easily. I added a layer of double sided foam tape to the Mini's hopper and left the protective tape (didn't remove the plastic layer to expose the sticky tape).
Here's a picture:

Not the best picture but if you look closely you can see the tape at the bottom of the hopper. BTW, you will need a solution to the safety slot behind the hopper. I was lucky and found a plastic piece that fit perfectly.