Now that I've verified that the engine actually runs and that the hull is sound, I've started working on other stuff, starting with the gauges. I want to get them all up and running like they should. That'll bring a nice comfort level for my wife and me.
Yesterday I did a tach test. In the morning, I removed the tach from the donor boat dash and temporarily installed it into the MC. When I applied 12v by turning the engine key to "on", the needle immediately jumped to zero as it should. A good sign.
However, in the evening after I pulled the boat out of the garage and onto the driveway to fire it up, the tach failed. Yes, it jumped to zero when power was applied, but it didn't register any revs. I tried it on all tach settings, but no joy. Dangit. Either the tach is no good, or the signal isn't making it from the engine to the dash. I'll be checking the wiring, but I also went ahead and ordered a new tach harness, since none was used in the current setup.
Work continues.