I believe Harrick mentioned he could create a couple skeletons to crank the engine. Either that or we put Harris to work again.
"I couldn't live with myself if I was beaten by technology and the undead at the same time. I can handle this!"
I'll cast treasurescent (8 hrs), detect magic, rapid burrowing (80 min), change into a dire badger, and scour the area. Can maintain badger shape for 8 hrs, 30 ft burrow speed with rapid burrowing (which I'll cast multiple times).
Note that detect magic and treasurescent works through 3 ft of dirt. Those should help find any kind of mass grave, if the deceased were buried with their belongings.