This is based on personal correspondence that I have maintained with all of those aforementioned, sans Lehman and Nolin now that both have passed though there are a fair few in the Indiana Nut and Fruit Growers Association and Pawpaw Grower’s Association that were right up there in terms of wealth of knowledge. Lehman was unique though. He was to pawpaws what perhaps Lang, Nugent, or Anderson were to sweet cherries.
The critical flaw in assimilating information is that it’s often out of date. This was why you assumed the Keedeysville, Wye, and Corvallis plantings existed, even though its been over 10 years since those specimen were alive.
It’s really not hard to get in touch with Neal, Kirk, Sherri, Johnson, Huang, etc… For me it all started with either a phone call, email, or some random encounter at some event.
If you’re using the information assimilated from their research papers, I would naturally assume you are in contact with them anyways, since that’s the academic norm.