I know this is an old thread, however I also have a lineman mini excavator with no engine and no pumps. I have retrofitted at John Deere Tandem Hydraulic Gear Pump from a salvaged combine, along with a twin hydrostatic pump from surplus center. If anyone is interested this is the pump I used for the drive functions. I am using mini cylinders that are driven off of the low psi pilot from the joysticks. I also had to supply my own pilot pressure by means of a pressure 400psi regulator.

