I've ordered some washers of the right size from an engineering supplier. Hopefuly that will solve the spacer issue.
Back to the whinning noise. I haven't been able to drive the car of course so still haven't tested the noise with the rear prop off, but I thought I could take a look at the TBox anyway to see if the INT shaft was loose. Drained the oil and hardley any game out. The plug looked ok, i.e. nothing bad on the magnet, so hopefully no damage, but would that make the noise?
No idea about the leak, everything looked ok, I will drain gear box and check that one too.