If on recheck the oil pressure is still low or Zero, I would be inclined to advise you to go back to Jon at Emperor and excercise your warranty options.
If the pressure is still Zero I see no point in pulling the box to check the timing problem as both faults are unrelated.
I am at a loss to understand why a perfectly good engine can lose its oil pressure under these circumstances.
Of course, you could always instruct some one else, to get a second opinion on the oil pressure, and perhaps Jon may be prepared to help you out with the cost of that.
Let us know how the second oil pressure check goes with the existing repairing garage.