I suspect a lot of that procedural stuff varied between plants and no doubt between years, though I haven't seen too many ADs and yes, I haven't seen evidence of the primer on interior or parts inside
I've seen TF gas tanks with no paint apparent on them, just the galvanized looking coating, and I've seen them with interior color on the face as you say, and one that had the turquoise body color on the filler neck, indicating the exterior painted after the interior was assembled
I've also seen trucks with an unpainted area where the tank would have been, sort of fogged at the edges as if they just skipped that part or there was a tank in front of it - can't say I've ever seen one painted behind the tank, but I might not have noticed
Bill
