I was wondering why some good earlier tv shows are never repeated when mediocre progs seem to be repeated on a regular basis. One that springs to mind that to me was hilarious was Rowan & Martin's laugh in.
R & M was very much of its time with very topical humour (loved it), so don't think it would stand repeating. I do agree there are some great programmes from the 50's to 70's that would still go well.
Gunsmoke, Maverick, Bonanza would all do for me