Though I must thank Denis for his unbridled kindness, the document I put together when I sold him my JOR was flawed.
It seemed there must have been some confusion in the translation of the biasing instructions into English, and that is what I used to bias the amp. There are 4 potentiometers in the JOR, one for each tube. The instructions I received stated setting one pot of each channel to 110 mV, the other to 0.0 mV. After having this pointed out to me, it was obvious that ALL FOUR tubes should be running at 110 mV.
I'll take full responsibility for the previous errors of my ways. I should have followed up with a confirmation of the instructions with Jadis - France, but I did not. My fault...