Dark Skies. It was x-files if set in the 1960s. But as it used music from the time, the classic music licenses have since expired and nobody is willing to pay enough to renew them.
Also, why in the world isn't The Twilight Zone (the one from the 50's) in the public domain? It already set up the genre, it has been exploited in TV with ads for sure for decades. Also, I think Rod Sterling is not alive since a good chunk of time, ditto with the producers. There no loss on torrenting that series. If any, it would help on sales on current sci-fi series.