Just dipping in on this post!
How did you get on with the gearbox Grah71?
i have the same issue with mine, AUB engine with ETB box.
options I have seen are
1. remove gearbox and send for refurb for £530!
Or,
2. find an alternative box!!
interested to know what other gearboxes fit onto an AUB...
(apologies if this is posted elsewhere on the forum)