The biggest problem is obviously copyright issues, on footwear, replicas can be 99% to an original and have no legal issue except being "unauthorized" but even unbranded footwear is in the clear. If it was 100.00% exact then there would be legal issues, which is why Nike hasn't bothered with the V1, V2, or HC designs. So if we had the correct upper, correct mid and out sole, we can have it made unbranded and later added on, there would be no legal issues. But, if a factory made it exact as Nike's, (correct stitching, branding and all) that's when they would step in. Even the Air Jordan replicas can look 99% exact to the original (and they do) but there's always 1 small detail that gives them away, and also keeps them out of legal trouble.
I know this because someone asked Nike about all of the Air Force I look alikes that are sold everywhere, the look alikes have the same basic outline and stitch lines, but that's okay by legal standards. Nike stated its only an issue if someone's design looks exactly like their's, take a look at the "Hardest Sneaker To Retro" interview. The only reason they got worried about a replica MAG is because they thought someone leaked a pair, but once they seen that the replica was not 100% exact, they didn't worry about it. If we can make them like the white sample pair of RD 's we can get away with that, no branding but exact in shape.