Shadow of Chikara is an interesting horror Western from '77 with Sondra Locke and Joe Don Baker. I saw it as a kid in the '80s on one of the terrestrial channels and it found it really scary (obviously doesn't stand up today). It's been re-released under several names like Shadow Mountain and Curse of Demon Mountain amongst others. I don't think the original print survives as it's never had a proper DVD release, just a VHS transfer. The full film is on YouTube in poor quality-
Cop with James Woods from around the same time as Bestseller is also a cracking thriller-
Ghost Story was a pretty good horror film from the early '80s- it was adapted from the Peter Straub novel and doesn't do it justice (it would be a series these days), but is still quite chilling in parts.