Runt
There might be a little metal tag about 1" by 3" held onto the outside of the center section by one of the nuts along the lower front. Some had the actual ratio stamped in them, some a letter code. After almost 50 years the odds of it being there, legible, and still applying to whats inside aren't that great. Only way to know for sure is pull the chunk/pumpkin, count the teeth on the ring and pinion gears, then divide.
Ed