ORIGINAL: beershark
Out of interest, Porsche Tiptronic boxes were/are sealed and weren't serviceable until fairly recently - thru OPC of course.
The Tiptronic gearbox for the earlier cars is made by ZF, and Porsche still will not repair, only replace them. A good indy or ZF specialist would be able to repair them, as they would any other auto box - they aren't "sealed".
I must say that Paul's Hartech solution seems like an extremely good deal to me.