Hi Peter
Unfortunately I can't remember the exact details as its been a while since I imaged with the DSLR and FS60. I continued to have issues with the correct spacing take up backfocus so set it aside though having learnt more about what's going on I may go and look again.
This is a link to the MMOAG guide to measuring the various distances. It's hardware agnostic and certainly a bit clearer than the "manual" you get with the Orion slim OAG.
http://astrodon.com/mmoag-optical-configuration.html
Where did you get the back focus figures for the Tak from by the way?