There is a brass insert with a cover just before the cutter assembly on the Palette. This cover was split and Mosaic was nice enough to send me a replacement, however while I was waiting I figured that I would try and model the part. I have not printed it yet as the replacement came in the mail pretty quick. At least this is a starting point. Unfortunately I do not know the model number of this part.
You will still need to press fit the brass insert into this cover as well.
The author hasn't provided the model origin yet.