Yes, it's clear that the best thing is to have the original boxes, the problem is that many haven't survived the deterioration of time and our youth. We've given them a very bad life!From my own point of view, I would rather have original cases and manuals, instead of reproductions, the value lies in originality where possible when it comes to physical cartridge collectors. However I am sure at the right price point some may wish to beautify otherwise poor cartridges boxes.
But if someone has the loose cartridges and wants something well-made and complete, even something better than the original with the look of the original, why not?
I know there's a lot of controversy surrounding the box issue. Some people consider it sacrilege to replicate them with the same materials as the originals and sell them as if they were originals. I know of several manufacturers who have introduced something custom-made into the box so they can be identified as replicas and thus resolve the controversy.
I have to admit that, when I restored the Magician Lord AES Cover, I was thinking about this issue the whole time. People are very fierce about this topic, from what I've read.
Cheers!