Of late, I've been really into Bill Boyd & His Cowboy Ramblers.
They sound like they look, which is wonderful, although every once in a while, they throw a polka track on their albums which is disconcerting. Another badass cowboy from this era is one Merle Travis, who's an excellent guitarist. We also, of course adore Django Reinhardt.
Now, Bill Boyd is not to be confused with Bill & Boyd, a New Zealand pop sensation duo from the 60's.