[AnthonyG]

Hey Old Henry, I got the same issues, I've come to the conclusion on mine it's the flywheel / pressure plate not balanced together. That will be rectified in about two weeks. Your mechanic probably changed the indexing the flywheel and or the pressure plate when reassembling. If your crank was balanced with the FW previously and they changed the index that's probably it, although if the pressure plate and flywheel were balanced together It could be that they changed the indexing on the PP to FW. In either case it's a PIA and a major dis-assembly fix. I'm commiserating as I'll be there shortly.
Good luck!