I was looking at lineposts in my collection and there is a few different styles of them.. Left to right (1) NGK 05 (2) This one not sure of marking as barely could see it but looks like "M" in a square but could be LM 1972 (3) LAPP 98 (4) OB couldn't see date (5) PPC 2011 (6) LAPP 1972 (7) NP 17 (8) Chance 82