I had sent the NG samples to the factory, they insist the products are fine with no problem, the marking difference is to prevent fake pirate copies so they will change a liitle periodly, and the mould is craft by hand so it will not look always the same. For the quality problem , the factory agree to add 5% No.2 to next order as a compensation, but they ask to increase the next order volume, because the new order is too small.