I am from just west of Cleveland Ohio, not too many miles from Lake Erie. I can verify foraging with my grandfather in the 1980's, along streambanks (digging RAMPS, if anyone knows what they are) and finding a number of Paw Paw trees as understory plants amongst the trees we were going through. The taller trees were all deciduous trees like Oak, Maple, Walnut, and Ash. I ride by the area on my motorcycle every few years, but it is mostly developed now. The Paw Paws were a treat, for sure, growing wild. I would imagine the wild-type would always just self select for the ones that could tolerate the weather/environment.
Anyway, thanks for bringing up the memories. I have never tasted a "named variety of paw paw, but the wild ones certainly impressed me when I was younger.
Lazarus