If he has MCA national show judging sheets, it would help you determine what level the car was restored to. Multiple sheets from different shows and difference judges would be ideal.
Concerning the MCA classes, you probably are not familiar with them. For Concours, there is simply trailered class and driven class. MCA has Occasional and Daily Driven classes, which are only judged on workmanship, condition and cleanliness (no authenticity.) The judging sheets for Occasional and Daily Driven are only a couple pages long while Concours for 65-66 is around 14-15 pages.