If I end up restoring the car, the fender tag has a hole rusted in it. It's small, and between numbers. It definitely doesn't interfere with reading or decoding the tag. I would try to procure a replacement so it looks nice. Is there something immoral about that? Especially if the original tag is retained as part of the car's documentation?
If your reproduction tag is documented by the original in both coding and format, why would there be an issue? No one quarrels with that concept.
The discussion is always around the ethics and implications of reproducing undocumented tags.
I've been working with, studying, and cataloging fender tags for over 20 years. I've seen thousands of tags from various years, plants and platforms. I still see new things (V08 on a '69 Lynch Road tag) and learn every week.
The amount of correlations (IF N96 then J25 except for.... type coding) and nuances (A code did not appear during that month/quarter at that plant. That code never appeared at that plant. That code started showing up during May of the production year) that occurred make it virtually impossible for the average (I'll look at my car and make a best guess as to what goes on the tag) guy to make an accurate tag for their car without extensive research and sometimes never (i.e. representing 69+ Lynch Road gate and base numbers).
Tags made by 'professional' tag makers are often easy to spot due to their misunderstanding of coding, guessing and unintentional errors so even paying somone to make a tag can have pitfalls. Buyer beware. There are a lot of crap tag makers out there right now.
Even tags reproduced from a broadcast sheet or other documentation are inaccurate or subject to errors due to not understanding what codes to use and when to use them from which plant. Again, buyer beware.
If you HAVE to have a tag to satisfy your ego, please, go ahead but please stop rationalize and justifying a relatively expensive inaccurate reproduction part that does not go with your car simply to ease your own mind, opens up questions as to your integrity and, unless you have directions to destroy your car when you die, lead to potentially fraud in the future to the rest of us.
No one can stop you from having a bad tag made for your car.
My two cents. Your milage may vary.