bkvail, this might help, it's an Army parachute repair manual that has info on your model:
https://books.google.com/books?id=2P8XAAAAYAAJ
As far as the speed issue, you can replace the old style clutch motor with a servo motor. If you go to Amazon or Ebay and search for "servo sewing motor", you'll see some options in the $100-150 range. You can dial down the speed and control the machine much easier.