@HmooseK , well I did some asking around to see if anyone had any information on the "Chestnut Colored" bean from Dan McMurray's collection. The gal that runs the Populuxe Seed Bank put me in touch with someone from the Dan McMurray Memorial Seed Bank and this is the reply I got...
"Hello Annette - thanks for your interest. We love hearing from people who are heirloom vegetable growers.
Chestnut Flavoured was in Dan's collection when we received his seeds in 2012. Unfortunately, we didn't grow this out for several reasons, but mainly because we couldn't find any information on it. We no longer have seeds of this variety.
I checked extensively online just now, including the Canadian Seed Library and Seed Savers Exchange, and could not find it. Quite a few of Dan's beans were not identifiable. "
Soooo, it looks like another one is on the way of the Dodo bird. Have you grown it yet, is it any good? If it is maybe give a name and add an a.k.a.
Sorry buddy that's the best I can do on this one.