System considerations for a 1970s occult game

...a culture that translates warm blood into cold statistics.

There is this idea I return to from time to time, which is a playing an occult-themed game set in the 1970s. Something I'm constantly collecting inspiration for, brainstorming stuff. These are mostly details little atmospheric parts and little atmospheric parts, be that comics, movies, books, anything.

And there is also the question of mechanics, something I'd like to elaborate on in this post.

An obvious choice would be Call of Cthulhu, but, frankly, I'd rather not, as I don't plan the game to be solely Lovecraft-themed. Of course, CoC can be used for any horror game (and my planned game obviously has a share of "Lovecraftianisms" in it), but still, I'd prefer something else, something that's not connected so strongly with the oeuvre of ol' H.P.

There is always my long-time favorite and go-to weirdo occult system, Unknown Armies. And there is the third edition coming soon. But, once again, it is associated with a very specific worldview, and a post-modernist approach, which I like, but the game I'm planning is, on the contrary, is rather modernist.

No time to explain, get inside the circle!

There are tons of horror systems out there. E.g. there is even  The World of Tales from the Crypt RPG, which would be thematic if I wanted to emphasize my game's connection to 1950-1970s comics. Then you have the generic horror systems like Chill (see also Cryptworld from Goblinoid Games), and even World of Darkness or, why not, WitchCraft could get a mention.

But if the game is set in the 1970s, why not have something that stems from the 1970s as well (yeah, this is a weird logical step, but you get the point)? Besides, I have a thing for the wave of OSR games coming out lately; their aesthetic and sensibilities resonate well with the game I have in my mind. I'm not afraid of this game turning into a dungeon delve into the old sewers either. That would be awesome. Though I don't plan it to be the main focus.

There are several sources I can use / plunder:

1. Fantastic Heroes & Witchery. I've mentioned this several times before. It has basically everything I need, though it lacks a couple of generic "investigator" / "citizen" type classes. The specialized classes and races are awesome, though. And there are the optional rules for dabbling in the dark arts, "Incantations" and "Severe Sorcery". 
2. David Baymiller of the OSR Library has a whole bunch of resources under the moniker Mythos & Mayhem. Including "civilian" classes, although I probably wouldn't need so much detail. + The much needed "Ritual Spells" and "Anyone can cast magic" sections.
3. There are approx. twelve million "Lovecraft goes OSR" titles from various game designers. As mentioned above, I don't want to go full CoC/Lovecraft, but these games still might be inspirational. I don't have Realms of Crawling Chaos, though I should definitely check it out. A game for Sword & Wizardry was announced today, called Eldritch Tales. 

And so on, and so forth.

Overall, the system has to be able to handle some weird, non-human classes, as well as your humble everyday citizens and meddling kids; it has to have a ritual magic system with dire consequences; rules for 1970s technology (guns, that is). An OSR system can do all this, although with the usual inherent caveats.

We'll see.