And, yes, the Mitsubishi engines were used simultaneously in many platforms. You're unknown bolt hole may be for a commercial application like a forklift or boat, a fwd application in a car model.

Part of your learning about the Mysterybishi is the zen you feel afterward. Having looked at the tasks you performed in 6 hours, I'd not scoff at that. Lots of things to keep track of and separate; but, I wouldn't knock this board or the history that it holds in your frustration. As a long time guy here, but not as long as others, I can pass along the lesson of patience, grasshopper.

The sorting of your no start is just for another day.