You have a 1962 GMC, made in Oakland, CA. The E on the end stands for the GVW, but I don't have any listings for that handy right now, but it is medium size truck. The GCW is the Gross Combined Weight, but listed next to that will be the GVW (Gross Vehicle Weight). List that for us if you would, but I'm going to guess that it is around 19,500.
Bill