a) There was no longer much of a distinction between the oil in the sump and the water in the coolant circuit (a la Third Policeman) - and the engine didn't much care.
b) Cobbler's children: the vehicle was assigned to the mechanic in charge of the workshop which kept all the site's vehicles & plant functioning, and thus was the worst maintained item on the site. And I wasn't sufficiently senior to authorise replacing it . . .