Trying to form an entire business around some small bit of technology is a non-started, imo. Focus on one area (eg the 6052 uc), blog with passion about what you're doing, build a following, and start up a Patreon. The long tail of the Internet enables business models that target tiny niches, so the cassette heads can find each other, and subsidize the creator of an ML model trained to invert audio cassette dub generational fidelity loss.

It's a scary leap to make, but if you can pay some bills following your passion, making things you need to build, then I'd call that a win.