I'm picking this back up, but my PCB design is in a sorry state, and I'm rusty on the circuit anyway. So my new plan is to build a perfboard version first, and then go back to PCB design.

So far I have collected nearly everything, but I can't find my chip tubes. I'd rather not take my breadboard circuit apart until the perfboard one is finished, because it's too darn fun to play with. But if I can't find my tubes, I might have to.