Vehicles were coming out of Ford plants like a sausage machine spittin weenies. If they ran out of shells it's quite plausible that plant management made the decision to keep going and use unpolished stock.
I went through this a bit during a Mopar muscle car restoration. A 4000 mile virgin had been found and one side of the car had a dominant amount of "anchor" stamped bolts, the other side with a "target" style logo on the head. Someone within the club staff sought to make that a judging standard. So by that rationale the line would have to stop if the left side ran out of anchor logo bolts? If we think Model As were built fast, imagine how fast those Mopars were being spit out of the plant in Hamtramck. But wait, we're out of anchor bolts!
Sometimes it's hard for a us singular enthusiasts to get our arms around mass production ideas. Horror of horrors, I have some nice stainless shells that I plan to paint black, and even an extra stainless radiator shell to be painted as well. Why not? It'll never rust and with a light wisp of etching primer 1st it should hold up really well.