Overton had no problems making M2 stocks for Inland and was not the only supplier to Inland at the time as HI stocks were also in the mix. I would not be surprised if M2 stocks that were made here during the war and went to Korea that went through a rebuild in Korea were stamped with the circle K. Any stock that was not in acceptable condition and was replaced by a new one made in Korea may not have been stamped as such. None of the M2 Korean made stocks I have seen have had the circle K in the sling well. I will say I have only seen maybe 6 or 7 of them over the years and not a one was walnut. Someone called it Foo wood but I doubt that is the correct name for the wood.