I can show you how to tune skis. I've been racing since I has a teenager. An experienced racer on the Masters, WMRL and NASTAR circuit.
Ski racers don't trust business establishments to tune skis. If we need a major bottom grinding or ski repairs, we would go to S&W in Concord NH or The Race Room in Lincoln.
http://www.theraceroom.com/
I have a portable unit and can show you at your work bench. A couple of beers and your good!