Truing a crankshaft is different then balancing it .Truing is only making sure that everything is straight /square and within clearance tolerances, balancing is manipulating the wieght to try and minimize recipricating and rotating harmonics. You cannot really balance a single cylinder crank only find a possible acceptable compromise fora given R.P.M.
I would easily trust Eric Gorr to rebuild my crankshaft but I am not sure that I could give him or anyone else enough accurate information about myself,mybike and my conditions for balancing.Without knowing exactly what you want for a given situation /RPM and living with the compromise in other areas it could be a futile experience for you as a consumer and him as a mechanic/tuner