Hi I'm just doing some research into my Grandad and I have the original of his "Release Leave Cirtificate" but not his service record. He was a driver and enlisted in 1942 for the Royal engineers. On the form there's a section titled "unit, regt or corps" and "869 M.E. Coy RE" next to it. I assume the "M.E. Coy RE" stands for Mechanical Equipment Company Royal Engineers and the 869 is the company. However, a 139 and a 138 M.E. Coy RE pops up at the national archives but I can't find any trace of "869". Would someone be able to tell me whether I'm right, the unit or what this number stands for.