Die Stamped writings on commercial barrels identify the manufacturer, the caliber, and provide safety information, on some brands. Removing those markings does not fool anyone as to made the gun, IF IT CAN BE DONE. I have seen and worked on barrels where the stampings could actually be felt, and seen( using a bore light) on the inside of the barrel. I don't know how anyone could file off those markings completely.
Care also needs to be given to caliber, and the depth of the markings. It may not be Safe to try to file off markings completely, because of the amount of metal needed to be removed to do so. I would worry, for instance, about filing off most GPR markings on a .54 caliber barrel, but be much less concerned with filing off the markings on a .50 caliber barrel of the same width.
If someone wants to file off a perfectly good barrel, its their gun, and have at it. The cost of replacing the barrel may be less than the cost of a new gun. If you want a pink rifle, who am I to object??? :idunno: :blah: :surrender: :hatsoff: