The way I look at it you sweat the details you want to sweat. If the motor originally was grey amd now is, say orange, then it's up to you to decide if you want those parts to look more original. And if you're cleaning parts now spraying them the 'correct' color isn't that great a step. Trying to find a correct date stamped generator or water pump just because it has the right date for maybe taking it a bit too far if you're not building a concours show truck.
