Matt; I don't think its a Weaver. They never did an engine that used the Type A truck. Plus the typical Weaver motor mount does not fit the truck. I am not aware they ever did a diesel with a different mount.
Steinzeit: the wheels are insulated on the spur gear side. typical plastic bushing between axle and wheel. yes the bearings are conductive.
Did K-Line ever make a truck with a removable bottom plate?