I just received and refurbished my very first treadle. It arrived in rough (not functional) condition. Yes, I took it all apart but took TONS of digital pics from every angle imaginable during the process. It was worth every minute of time spent cleaning too!
My neighbor's physical therapist has prescribed treadle work for her bad ankle. The action is perfect, not too much from an impact perspective, and easily repeatable. Her response? Darn! I have to sew more!!! :-)
Now, I just have to find her a repairable treadle or I think I'll be losing mine! Warning, it's addictive.