Something I've been thinking and suggested to at least one other community creator here was to sift through some of the threads discussing communities folks are missing from reddit.
See if any of the people mention a community like this & reply to them there (maybe add an @ mention if unsure if it will notify them) telling them you've made a community like the one they miss. Also if you haven't already, you might mention the community in [email protected] and similar communities in other instances.
Also if you're wondering how I found my way here, I'm a weirdo that browses posts sorted by new to try to find different stuff.