The Blue Sky import mark does hurt the value of a carbine. A few have the import mark stamped so heavily that a flat spot can be seen inside the bore. Most Blue Sky's were used by the Korean army, which means that they had hard use. When they ran out of spare parts, their armorers sometimes made repairs that we would consider unsafe; e.g., a broken lug might be welded back on a bolt. Carbines that were refinished look like they were rubbed with chalk, & the phosphate can be abraded by rubbing with your finger nail.