Wow slaw, two songs I haven't heard. So Steve Miller's "Mercury Blues" is a different song the Lindley's? I admit I haven't heard it. I saw The Steve Miller Blues Band (his original band name) in '67, before the first album came out, with Boz Scaggs playing rhythm guitar (a Gibson ES-335) only, not singing.
I'll bet Chilton's "Summertime Blues" is an interesting version, but haven't heard it. So much music, so little time!