I was in a hurry so got a place in Melbourne to source a replacement diff and fit their after-market actuating kit (a knob on the floor). All up about $2600 (about a year ago). If I wasn't in a hurry, I'd pick up a LT230 diff much cheaper privately - even on ebay they seem to pop up fairly regularly for around the $400 - and I'd lash for a 2a factory lever/actuator set up. Don't bother trying to find the missing internals and rebuild the diff. Just replace the lot.
cheers

