I'll be interested to hear if you have any joy.
I took a Robur hopper to a "plastic expert" a few a years ago expecting that they could cut it down with a hot-knife or similar and they wouldn't touch it. These guys bend, shape, cut all sorts of plastics and wacky compounds. Apparently they said it would shatter unless it was cut within a few weeks of manufacture.
If I ever get hold of a broken one I'll have a play and see if they are right.