Fidelity Research FR64s Headshell dilemma

If to look into details you'll find that  the world isn't perfectly round. But devil is always in the details. 
But better to believe in round globe. 
Although of course 0,001 mm is very important as feeling of mindfulness can be lost.
16.863 or 15.948 that is the question for the doctor.

If we do speak about scientific arguments we have to use science principles.
I can see hypothesis - geometry. A lot of very exact calculations from derived data. Although I was thought in the university that after hypothesis you have to do experiment which must be reproducible. I do see a lot of calculations. What I don't see actual measurement with test disc using dedicated setup like old days system produced by Bruel & kjaer. So I think that Japanese geometry is problem related to that we can speak a lot, make a lot figures that manufacturers are stupid. Although at the very end measurement is the easiest way to decide.

Nandric, show me measurements not geometry assumptions.
I don't neglect models.
I am not believer in Stevenson or Baerwald superiority. 

Yes lewm measurement is a key. In the modelling then geometry was used to measure land in ancient Egypt results was easier predictable. Tonearm is much more complex.
To order such LP with 1 kHz tone is not big problem these days and even it's not expensive. Just someone has to make  methodology and try it for the sake of humanity :) After measurements we can discuss if 1 kHz tone is the right one but it will be figures not modelling. 

  

Lewm, tonearm isn't a geometrical object it's also a mechanical one.
Yes Logfren and Baeward relied on geometry as we do build models of real world - it's part of science. After making model we do measurement in real life if results are as predicted = we have made good model.

There is services which can do such single sided like this one
https://www.onecutvinyl.com/
As about frequency yes it's a matter of methodology of experiment. I do believe that it can be very interesting topic. 

I do remember as story of SAEC then the first series was so condemned by alignment geometry specialists that they have changed into more normal one after 308 series. It's obvious that next series was more geometrical :)
So Japanese know about geometry for sure. 

SAEC was superior brand. They were used by Micro Seiki, Technics, Victor as upgrade of stock tonearms.
After CD they have just ceased production of tonearms.

they disappeared not due to geometry but due to CD era.
https://www.analogplanet.com/content/saec-again-producing-classic-double-knife-edge-bearing-tone-arm

I have experimented with my 308SX they weird geometry works better that Stevenson. I have tried to move it to Stevenson although it tracks worse than with SAEC weird one, I am not expert like Raul but I really like test disks :)

Today I did some observations and decided that topmost exact what I can squeeze is ~ 0.5 mm for set up. Maybe some day Mitutoyo can do special caliper for the purpose?