hhmmm...Lightnin' Hopkins....Jorma Kaukonen...are two that come to mind. I know they both often used J-50s(same guitar), but exactly which recordings, I'm unsure. Early Hot Tuna recordings for JK, Arhoolie recordings for LH. there is alot of good video footage of Hopkins available,i.e. the documentary film 'The Blues According to Lightnin' Hopkins' by Les Blank. I'll think of more over time.
Just remembered, there was a Jorma Kaukonen solo album, very early '70's, called 'Quah". Excellent album, and I'd wager he's playing his '58 J-50. His more recent 'Blue Country Heart', show a pic of him playing Old Trusty(my term). That album is also excellent.
Russ Barenburg has been playing a 40's model for quite a few years. He played one on some of, if not all of an album with Jerry Douglas and Edgar Meyer called Skip, Hop and Wobble.
Check out Nickel Creek albums from the last 7-8 years. Sean Watkins plays a vintage J-45. 21st of May being a good song example. A lot of his solo stuff also has the J-45.
