I have had a horrible time trying to find pictures on my photobucket account the last few days - I know I have pictures of the bottom sides of both styles 101 - but can not find them (also can't find the pics of my Minnesota and treadle table, and a few others . . .)
Anyway - this is a rewired plug showing the old style "ends" that connect to the machine. This one is for a 128 but is the same as what is with my 101.
I did find this picture - showing the built in control box. Notice the two copper pegs extending for the box with all the round airholes? that is where the "cord" plugs into the machine. That is the "foot pedal" for this machine. The knee lever is just a lever, and pushes into the end of the machine to activate that control.