As for the tape type and bias - you are making the huge assumption that I have any idea what tape I am using. Rev knows what tape he buys. I buy whatever I find on sale. I want to use the Otari's oscillator to help me calibrate it to the tape, have not figured out what the procedure is.
But... you're Captain Tape Deek.
I don't know that I ever used the oscillator. Our department bought tape in bulk (Scotch 207, IIRC), so the machine was probably tuned once to that tape then those functions were never used again.
Is your manual paper or pdf? If it is digital, email it to me so I can refresh my memory.