TOPIC: '72 105hp

I just picked up a 16' Chrysler challenger with a 105hp engine. Seller states that the shifter is locked up, neutral start not working, no spark, etc. the boat and motor have not been registered since 2001 so it's been in limbo for over 24 years. I ordered a Clymer book for the engine off eBay to help out. Never worked on Chrysler motors at all, always Johnson and 'rudes with a Merc peppered in once in a while. Looking at the 105 it really looks simple, easy access. Hoping to glean some advice and pick a few brains here along the way to get her running and back on the water. Any help would be greatly appreciated.

The tach has two lugs and they are not labeled. Anyone know which is signal or battery?