Hello Paul,
What part of the country are you, or the Cadet you are interested, in?
Culver specific pre-purchase inspections are tough, only a couple people in the country that I would consider Culver experts and some, if not most, are not A&P IAs! Obviously the mechanic or shop you are looking for will be familiar with antique wood and fabric airplanes.
David Pasquale in PA is a Bellanca expert and doing a great job getting a Cadet back in the air. I have an A&P IA friend that has restored and flown many Cadets that I work with, we are located in Atlanta GA. We would be happy to travel (within reason) to inspect a Culver for you. I don't have much experience with shops or mechanics out west so can't really help you if your in that direction.
Best regards,
Joe