Have you contacted Thoroughbred Daylilies in KY? I found their price list from 2015 and they listed both Daniel Boone and Jefferson Davis.
Oops! Sorry, I just looked at the website for Thoroughbred Daylilies, which I should have done before posting, and now I see that The Rices are the owners and you have already contacted them.
I can't see a way to delete my original post, which I would have liked to have done before other folks had a chance to read it.