"Apparently Big Bill Broonzy was also a fiddle player, though I've never heard anything by him. And Stephan Grapelli could turn his hand to it if necessary." Ray

There's a few records of Big Broonzy playing fiddle on pre-war blues reissues. Check Old Hat CD-1003; Folks He Sure do Play Some Bow, which is the companion to Violin Sing The Blues, mentioned already in this thread. Also RST JPCD-1513-2; State Street Ramblers, Vol 2. Also, check the Document reissues of Big Bill which will certainly include some other records of his fiddle playing.

Incidentally, Lonnie Johnson was another fine blues violinist whose talents on that instrument were overshadowed by his skill on the guitar.

You can hear him playing fiddle on the Old Hat reissues.