Your drawing looks like something Tom Miller made around 1982 or so for Al and Teresa Hemminger. This was before Teresa and Sem got together. Could be that one, or Semcycle may also have made a version but I don’t remember seeing one. The one Tom Miller built was based on a high-end child’s bike with 12" wheels, with various add-ons that allowed it to be put together in multiple configurations. I probably have pictures, but unfortunately they are prints in old photo albums (at best; at worst, 35mm negatives).
I hope that helps. You can try contacting Semcycle directly: firstname.lastname@example.org, or Tom Miller (phone only) at 1-765-452-2692. That’s in Kokomo, Indiana.