In addition to the Skillet Lickers I have been listening to some other players who in my mind's ear showcase the principles of Dan's Rhythm Essentials:
Wayne Henderson backing up Kirk Sutphin on "Old Roots and New Branches"
Annadeene Fraley backing up J.P. Fraley on "Maysville"
Susie Goehring with Rayna Gellert on "Starch and Iron"
Dirk Powell on a variety of recordings
There's a bunch more, but I've been trying to focus my attention to get the most from the Essentials.
Just an aside, for some recordings I have found that the rhythm guitar is better heard on my car speakers than anything else!