Yea, I think they were kinda smart at this show : 5 classes :

60 and prior cars
61 and later cars
60 and prior truck
61 and later truck
motorcycle.

not a lot of confusion or fudging there .....

BTW, a 1964 International cabover won the 60+ truck - had 780,000 miles and guy had worked his butt off restoring it. He said it spent it's life hauling oranges in Florida, and he was one of the original mechanics working on it for the company......