Cheap headers...
Yeah, floating flange gasket is common (prefered as you can clock the hard exhaust pipe or the bolts if the exhaust is floating too), and the welds inside the pipes are easier to do than exterior welds. Id stay with the flat flanges over the lame "O-ring" flanges any day. Scratches are no good but other than that........? Those 3 days on the dock were probably in the "beat to ****" pile on receiving. And a 'new' part should not have rust on it already.