While I finally got around to reading Bruce Bastins' Red River Blues, I did a google search to find recordings / information of bluesmen Richard Williams (b. 1887), Robert Dennis (b.~1914) and Emmet Murray (b.1911) mentioned in the book. I ended up on the State Library and Archives of Florida, who have the original recordings mentioned by Bastin (on p. 45, in my edition). Copies of the recordings could be bought from them, if I understand correctly. These recordings were originally published as a two LPs called "Drop On Down In Florida: Recent Field Recordings Of Afro-American Traditional Music", Florida Folklife LPs 102 & 103, 1981. http://www.floridamemory.com/Collections/f...arch_simple.cfm

Moreover, they have a very nice Podcast featuring both artists mentioned. Williams is performing with his daughter, Ella Mae Wilson singing, among other things. I don't think this has been mentioned here? Anyway here's the link, and what they have to say about the podcast:

" This podcast expands on some of the exhibit’s lesser known Florida blues musicians by presenting recordings captured live from the Florida Folk Festival stage alongside more intimate performances documented by Florida folklorists working in the field. Everything from “Diamond Teeth” Mary and Willie Green’s bawdy blues, to Roy Bookbinder’s finger-style rags, Johnny Brown’s slide, Emmett Murray’s electric guitar, and Moses Williams’ diddley bow. Performers Ida Goodson, Ella Mae Wilson and Richard Williams, Charles Atkins, and Robert Dennis—it is all here."

Scroll down to Podcast #8:

http://www.floridamemory.com/collections/f...e/sound_pod.cfm

FWIW this podcast is about 1h 15 minutes long, so downloading it first before listening might be a good idea. The material varies from country blues field recordings to modern day electric blues festival performances, so if you want to cherry pick, having downloaded makes things easier.
Somewhat frustratingly there isn't any track listings or narrations after the very beginning, so it's just one song after another, without any track information. From what I could gather, the high moments (at least for me) were:

song #1 (after the opening tune and narration) at around 03.10 "She's A Fool, She Ain't Got No Sense"
Guitarist Emmet Murray tunes his electric guitar really low, around C, and gets a wonderful twangy sound to his fingerpicking, which reminds me where much of the rockabilly vocabulary originally came from.

song #4 at around 12.00 "That's All Right" has Johnny Brown playing a Gospel slide number.

song #6 at around 15.30 has Richard Williams and his daughter Ella Mae Wilson doing a very intimate and enjoyable duet version of "Careless Love" with a slide guitar accompaniment. At one point you can hear a rooster crow at the backround! Smiley

song #7 at around 19.00 has Moses Williams performing "Rolling and Tumbling" on a diddley bow. Interesting sound for sure.

song #8 at around 21.00 has guitarist Robert Dennis (who is a cousin of the forementioned Richard Williams, who can perhaps be heard commenting on the backround) performing a song called "Early One Foggy Morning"

song #11 at around 37.00 has Emmet Murray returning with his low-tuned electric guitar for "I'm Gonna Dig Myself A Hole", another pre-rockabilly gem.

song #13 at around 41.30 has Moses William returning with hid diddley bow for "Sitting On Top Of The World".

song #16 at around 50.55 has Richard Williamson and his daughter Ella Mae Wilson returning for "Polk County Blues"

song #18 at around 58.15 has someone doing a slide version of "I'm A Stranger Here". Could be Johnny Brown, if I'm not mistaken?

song #19 at around 59.35 has Emmet Murray returning again with his plonky electric guitar for "All You Old Time Rounders Better Lie Down"

song #21 at around 01.06.40 has Richard Williamson returning, this time without his daughter, for a lovely song called "Old Forty Blues", which apparently is a version of a song called "Further Down The Road".

song #23 at around has Emmet Murray returning once again with his electric guitar for "Mobile Blues".