As Frank said, no wiring diagram except in the parts manuals for electric start motors.
There should be a choke solenoid which mounts on the bottom of the carburetor bowl for that motor. Manual start motors did not have the correct carburetor bowl for the choke solenoid.
The choke solenoids and electric starters both started as 6v accessories, but I believe around 58 or 59 they went to 12v. 6v starters are fine with a 12v battery… 6v choke solenoids WILL fry with a 12v battery.
So use a 12v choke solenoid or 6v with the correct resistor in the wiring.
The only switch for the choke is on the dash which for that motor would have been a push button.
You said that motor has a long shaft gear case, and you want to remove it for weight issues… the long shaft kit weighs only 5lbs and the transom height of the boat is what will decide if you need a long or short shaft motor. 15″ for short shaft, 20″ for long shaft. Neither will perform right with the wrong length motor leg.
