I reviewed the pics of the first six signs. All six signs are cut where one side is straight (vertically) and the other end is cut like an arrow pointing the way.
The sign you found seems like it is uneven on both sides.
Plus, all signs, so far, can be read from the front side. If you cannot get close enough to read it, what is the purpose of WGT putting in there. That would not make sense.
Regrettably, I do not think that is the sign we are looking for. Can't be sure unless can get to the front side and read it and, if you cannot, kinda rules that one out. IMO
BTW. I was wrong that all have two signs on post, some just had the one.
Here is the sign you found enlarged: