Another set of thoughts: the problem with radio as a medium is that /nobody/ listens to that medium anymore--it's been eclipsed by streaming services, to which everybody listens. Of course that's not entirely true, and might be amended to say that nobody young listens to radio, but the notion of broadcast as a didactic medium, via which one can influence how people think about and perceive music, that's dead as a doornail. The Secret Museum at WFMU https://wfmu.org/playlists/SM was close to the sort of thing I imagine Paul-Emile doing, but that was, god help us, 20 years ago. Still valuable, still marvelous, but gone with the dodo. Citizen Kafka died in 2009 https://en.wikipedia.org/wiki/Citizen_Kafka but Pat Conte is still with us: https://www.conduit.org/17/conte and https://patconte.bandcamp.com/ 

Oh but I LOVE that music. See also https://jalopyrecords.bandcamp.com/ but what's missing here is the narrative for the music's context. We used to get that from "liner notes" and from books, and I have a damn wall of music-related books that I'm forever discovering new stuff in, and making additions to (awaiting the arrival  of two recent Robert Johnson biographies as we speak). But as for audience for what I know, think I know, want to explore further 

The Secret Museum has migrated to CDs ...https://www.amazon.com/Secret-Museum-Mankind-Music-Africa/dp/B000000G9K etc. ... available streaming too. 

Another toiler in these vineyards is Cliff Fernald, http://www.rootsworld.org/ who ran an obscure-world-CD store for years but gave up that business in the last year and now does an online 'zine http://www.rootsworld.com/rw/ (I'm sure Paul-Emile knows these folks, or at least about them). Cliff's operation has always been hand-to-mouth and is now supported via Patreon and other crowd-sourced appeals.

I know of a few other enthusiasts of similar kidney, but none of them have (or even seem to want) anything like a mass audience. Of music journalists, whose function is to point readers to stuff they might want to know about, the most prominent of the present is probably Amanda Petrusich, who mostly writes for the New Yorker. Her /Do Not Sell at Any Price: the wild, obsessive hunt for the world's rarest 78 RPM records/ is excellent. 

So I come down where I took off: this mania for the musically peculiar, elusive, undiscovered, delicious is pretty much fated to be a mostly-private mania. Today's discovery of the moment, thanks to your question:  https://johnandalanlomax.bandcamp.com/track/hard-times  

oh my.