From my research the complete assembled engine with the bellhousing, sheet metal, water pump, thermostat housing and outlet, the harmonic damper and spark plugs were painted. The spark plug porceline was masked off with a cardboard tube but not the steel shell. After it was delivered painted to the production line the accessories were added such as the starter, generator, carb and spark arrester, breather tube, fan, distributor, etc. So these items and their fasteners would not have been painted the dark gray that the engine was.
Now mind you, the engines in those pictures were going into 1936 Chevy automobiles. In the film it appears that the fan was also painted the same shade as the engine. That was not the case for the AD trucks where all the bolt on stuff was semi-gloss black.
Not to far Gus, does give us a glimps into the assembly line in the late 50's. Hadn't seen those in a while, fun to look at must have been a real hell hole to work at, I know it would have been for me.
