Wonder if something like modeling clay that dries could be used to fill the vin, be painted over and then the dried clay removed with a sharp scribe.......... Or, silicone sealant.............
No matter how exacting the restoration to replicate original finishes, in the flesh, i believe it would be easy to tell a "perfect" "like original" restoration from actual orignal. I say that because ANY original machine would have to have at the very least, some patina, somewhere. And, patina, while being replicated by forgery, would still be difficult forthe forger to determine what certain parts should have patina as well as what kind of patina is appropriate for these certain parts.
I'm going to stick with, "Original happens only once."