Dear @lohanimal : In my last post is an answer for you can't have to worry about, go with 230mm.
Now if you ask to MINTLP that you need the protractor for a tonearm with 245mm ( FR/Ikeda spec. ) and Löfgren/Baerwald alignment he will does and will works fine with your tonearm and any cartridge. In this way the P2S will be: 228.14mm and this is the distance to mounting your tonearm.
Btw, almost all internet alignment calculators give you the set up parameter values for you can make your own protractor or for you can confirm if the protractor you are using is rigth on orv is different like your Clearaudio.
R.
Now if you ask to MINTLP that you need the protractor for a tonearm with 245mm ( FR/Ikeda spec. ) and Löfgren/Baerwald alignment he will does and will works fine with your tonearm and any cartridge. In this way the P2S will be: 228.14mm and this is the distance to mounting your tonearm.
Btw, almost all internet alignment calculators give you the set up parameter values for you can make your own protractor or for you can confirm if the protractor you are using is rigth on orv is different like your Clearaudio.
R.

