Mercury 500 tiller electric start 1972

[Old fellow]

I recently bought this old 1972 Mercury keighfer 500 59 hp tiller controlled outboard .
It is in overall ok shape other than the wiring harness is all deteriorated. It is electric start also has a start rope.My question is will it get spark to the coil and run without a battery ? I plan to replace the harness clean the carbs and new plugs. Can anyone tell me anything about this motor.

 

[racerone]

Needs a new water pump impeller too.----Post compression test values here as well.

 

[Old fellow]

Well done compression test today and have 135 psi on all four cylinders. Which pleased me. Snow I need to check the switch box coil and other components to see if they are good . I can’t find a manual on this old girl any one with tips or tricks to check the things out would be helpful. Even better if someone has a manual to share . Thanks