If by “single pedal” you mean a single action, I’d be very interested in seeing it. By my count, there were at least nine different types of single action mechanisms used in the 1720 – 1820 period (crochet, bequille, fourchette, cheville mechanique, 2 kinds of sliding bridges, ring, rotating blade, and crank). I’d like to see how yours compares. I also believe there’s a ready market for a single-action pedal harp, if it can have a reasonably-priced mechanism.