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Also not a lawyer, but here's what I recall: If you are a shop, and you produce copies of something with the intent to sell it, that's commercial use. If you offer some kind of production service, and someone hires you to make produce something, you are acting as their agent. If they have the right to make copies themselves, you can make copies on their behalf.

I cannot offer and advertise this specific service. I can produce the part if somebody orders it.

I could order a 3d print of a part from somewhere; that somewhere's core business is not printing that specific thing.