I had one about five or six years ago. I built it into a box and hooked up an electric hand mixer to it so I could have both hands free for adding the peas.
It worked pretty well for cowpeas, so-so for butter beans. I enjoyed it but it only lasted two seasons.
Now I have a larger version, electric, also called "Mr.Pea Sheller" (what's up with that, eh?). Although it was just over $200.00 I went for it knowing I could grow enough peas and then sell enough peas for it to pay for itself. The prices range up to $289 depending on the company. I found Fleming Outdoors to have the best price plus Customer Service (I contacted them, the owner replied) was the greatest.
If you are wanting to stay away from reliance on electric I have no doubt this one could be rigged up to operate by hand or even bicycle because it operates on a pulley system.
Shoe