Well don't quote me but every original one that I've seen were black. Again, locic tells me that like the engine which was panted (dark gray) all of the items that were bolted onto it like the starter, generator, fan, distributor, reather,etc., were black. So it seems to me that the mirror arms, under carrage spare carrier, running boards, bed wood and runners were all added after the truck was painted. The only exception was the side mount spare which was assembled with the box and fenders and all was painted at the same time.
Denny Graham
Sandwich, IL