Probably the 3rd Battalion, ROK Marines. Protected left flank of 1st Mar Div, swept the Kimpo peninsula, and took part in the liberation of Seoul.
The ROK had a Maine unit attached to the X-Corps that I frequently came across in the Inchon-Seoul area in 1950. They had the same field uniform as we did right down to a Marine (ROK) emblem and the letters ROK printed over the emblem on the same pocket that we had a US Marine emblem. Does anyone know the desination of the ROK Marine unit, i.e., what was it a division, brigade, regiment ??? Don Gill