Ken - I am trying to remember back to when I visited our sickle suppliers (Kondex and our own plant in Hamilton, Ontario) and I believe both used hydraulic squeezers. That was 20 years ago so my memory may be a bit off on that but there was the need for speed supplying tens of thousands of sickles per year, keeping noise down, and quality. Of course the type of machinery they were using was way out of the price range for a dealer's shop but I was thinking a Cee shaped unit with the proper punch and anvil hooked to a hydraulic source you might already have in the shop would work well and may not be cost prohibitive. Doing the same thing with air - shop working pressure for air is so low that a squeeze type rivet set would get to be very large to get enough force to form the head while oil hydraulics retains a reasonable size. In our R&D shop we set rivets for testing different sections by laying the sickles on the floor and using an air hammer with the right tool end but it was always noisy and the pneumatic hammer would never give the hgh quality rivet job of the hydraulic squeezer.