This is a real long shot and I know transmission plates have been mentioned before. The A10 transmission plates are different to B31 plates. Also A10 plates have kinks in them on the left hand side (I think - it's a while since a did an A10 engine change). It may be possible to muddle up the engine / transmission plates and end up with your gearbox offset. Like I said, it's a long shot but worth mentioning.
