It is also possible that the proof sheet alignment was not replicated in the production sheet. I've only seen a few proof sheets before from other makers, but they were smaller than the production sheets; my guess is to make them easier to pass around the office for comment and approval.
I don't think the other ATC cards hold a candle to the ones made by the Obak/Pet/Kopec printer. Look at the depth and quality of image on these:
That's a lot more lithographic layers than the typical ATC product. The best of the other cards still have a more stylized, less layered quality:
As for T218 sheet alignment, I offer one humble piece of data:
