You won't find the duckbill eliminator in any USD parts diagram. We introduced it about 8 years ago to replace the duckbill which can be fidgety to keep in place when installing hoses.
Original Duckbills were made from rubber and had a tendency to either turn to mush or get extremely brittle after a few years. The new duckbills in the website store are made from silicone rubber and have none of those problems.
Click Here for Duckbill
I would highly recommend a silicone main diaphragm as the originals were once again made from rubber and no matter how well stored they have degraded over the years. The new diaphragm will lower the effort needed to get the air flowing and will improve or lessen the work of breathing.
Click Here for Diaphragm
A standard service kit and possibly a new HP seat are about the only other things you would need to get a Jet Air up and running 100%.
You should use the Mistral service section of the manual. Everything will be the same except the Jet Air does not have an indexing pin that goes between the body and cans like the Mistral. The body in a Jet Air can only go in one way where the outlet is facing toward the horn. They are simple but very reliable regulators. Although they lack the improved venturi nozzle of the Mistral, when used with low pressure cylinders they are fantastic breathing regulators.
Click Here USD Manual
Click Here Jet Air PDF
I moved your post to the Classic Vintage Diving section because the Jet Air is a "Classic" 
