I was stationed about 10 miles from the DMZ in 1991. The ridges around there all have numerous defensive trenchlines and defiladed bunkers, there are range cards engraved and painted and inlaid into the stone of the trench rims. Read "This kind of war" by T R Fehrenbach. It will answer almost any kind of question on the korean war. I also found the memorial to the Commonwealth Brigade one day. Very impressive. The South Koreans, at least of our generation, are very appreciative of our and our allies' sacrifices. My houseboy (in his sixties at the time) said he carried an M1icon while in the ROK army, and it was very heavy. He was very small, just over 5' and skinny. He put 3 children through college thanks to US GIs.