I’m putting together a modern campaign using the Twilight:2000 setting. With the loss of high tech capabilities, no cell phones, internet, etc, it gets that 1920s vibe back, but dressed in a modern day post apocalyptic style. Strange cults appearing in small war torn villages in the polish countryside, strange creatures spotted in the shadows of the ruins of cities that were hit with nukes, etc etc. Maybe New America has some affiliations with the great old ones. Maybe starting WW3 was the plan of Nyarlathotep. I think a lot of the published scenarios could easily include Mythos themes, especially “black Madonna”