In order to provide a ground for the oil pressure sending unit, I removed some of the cushion from the large adel clamp that holds the sensor, and scuffed it up with my abrasive wheel. I then soldered a ground wire to the clamp itself. Once the sending unit was installed, 1/2 the clamp is making direct metal-to-metal contact, hopefully providing a solid ground.
I then fabricated a length of battery cable to connect the starter to starter-solenoid. Cut to length, then crimped connectors to each end and applied heat shrink.
I then cut a length of batter cable to connect the master solenoid to the starter solenoid. Have not crimped the ends on yet.