Hi Sam,
No, I don't have an Amadeus, so I am not trying to tell you what you should do. But I am really curious about the turntable and am trying to learn more about its tonearm/cartridge geometry.
I guess I really don't understand your question. As far as I can tell from reading the Amadeus blog and the owner's manual, you're just supposed mount the cartridge in the fixed headshell and be done with it. It seems to be impossible to adjust the overhang or the tracking angle. I don't understand what you mean by, "the nude point of the protractor is 1 7/8 inches." What exactly is your question?
On the Amadeus blog, it states:
"After my investigations, I decided to relieve users of Amadeus of the issue of setting tonearm geometry and to use a fixed geometry. Based on the comprehensive analysis of J.K. Stevenson in the May and June 1966 article Pickup Arm Design and based on the dimensions of several phono cartridges in my inventory, I designed the tonearm for Amadeus to have a fixed tracking angle of 19 degrees and an overhang of 0.5."
...and...
"The Amadeus Headshell is factory fixed in position. The Well Tempered Lab unequivocally reiterate that it should not be moved."
The owner's manual states:
"The headshell is fixed ex-factory in the optimum position. There is no provision for over-hang adjustment."
This seems to imply that all cartridges in Mr. Firebaugh's inventory produce an overhang of 0.5" when mounted on the fixed headshell of the Amadeus. That means every cartridge he has must have the same distance between the cartridge's mounting holes and the tip of the stylus. Given the wide range of this dimension that I've found among cartridges in my experience, this is difficult to believe. Perhaps it would be helpful if Mr. Firebaugh told us which particular cartridges produce an overhang of 0.5" when mounted on the Amadeus??
-Bob