Is there a local community college? Offer to teach a PPL ground school as a continuing education class. When I was in your shoes, I found a nearby CC that offered a PPL ground school and the guy teaching was doing it for fun and not looking to instruct. I asked him if I could come to the class and make a presentation for my flight school. Guess nobody ever thought of that. I got three or four students from the 10 or 12 in the class.

If you are willing to do BFR's, put a flyer at the local airport bulletin boards.