I'm pretty sure that's a VW Type IV and not a Porsche 356 engine. Porsche 356/912 engines have one bolt to hold on the crank pulley. VW Type IV engines have 3 bolts.
I'll offer your services to Porsche dealer. Them covering the airfare might be cheaper than the charge out rate for tuning. Not being able to plug the carbs into the diagnostic computer might just stump them!!