1) Body: You will need to cut the body in slicer (best way to cut it is vertically in the middle). You can add some connections (feature from new prusaslicer- 2.6.), but there is no need. I just designed and printed washer for Feet in the middle (like on the photo). And than it will held by screws that are connected to the Aluminium extusion profiles. If you want, you can use superglue on the frame.
4) Pivot: It is designed for M3 screw and nut. It is better to put there distance ring from original model.
Filament cutter used on this machine: https://www.printables.com/cs/model/607871-pet-cutter-extension
The author remixed this model.