He reports that the shell grinder works like a charm. They’re running about 30,000 lbs in an 8 hour day ~2TPH, and are very pleased with the performance. They run it regularly, and the wear parts are all still in great shape, hammers included.

Later update, after 2 years of use:  The customer has run so much material he has ordered a replacement screen and needs a new auger for the screw conveyor.