Johnson control swap or adapt

[havingfunyet]

I'm in the process of putting a 1983 johnson 70hp J70ELCTE on our toon. I'm removing a 2001 35hp Johnson J35VL3SIE. The 1983 did come with a controller and wiring harness, however, the harness is cut in several spots, I'm assuming that the cut wires were from gauges and switches.
What would be the best option for the controller?
Leave the 2001 and adapt or find a wiring diagram for the 83?
I've looked online for the service manual 393765 for the '83 johnson and found several of them which vary in price and size (Some as much as 100 pages) so I'm hesitant to order one without knowing which one is real or not.
Any advice would be greatly appreciated.

 

[havingfunyet]

I found a harness adapter 423-4644 on Amazon tonight for $80.
Will definitely save a lot of work. Says it adapts 1976-95 johnson engine to newer controller.