I spoke to Mark at
Italian Race Services and he said that while he has not done it himself, it is possible without too much difficulty as he's seen it done. The biggest problem, as he saw it, is in getting all the required parts. As well as the gearbox, you'll need a flywheel, clutch, clutch cable, manual pedal box (bolts on apparently) propshaft and starter motor as they are different between manual and automatic. The starter motors are fitted on the other side on automatics. He said the conversion he saw used a 132 gearbox.