Not to piss in your Cheerios but is there a demand for an all 50s band where you live? It just seams to me that the people that grew up with that music would all be retirement age and probably not really into the bar scene.
I used to play a lot of Legions. The gigs tended to start at 2:00pm. There where also evening gigs that worked around suppers.
You can get a good crowd, and a *drinking* crowd. However, they didn't pay very well