I'd agree about it probably being manufactured and not a one off tool maker produced item. The storage box? Maybe not so much. Yeah that box looks to be well made and finished, but I'd agree with Dave, that short hinge length seems a poor cost cutting decision given what most of these squares and in general the fairly high additional price for even a simple storage box are. So that might have been made by the previous owner. A Google & Ebay image search doesn't return anything like it that matches that base shape and what looks to be a proper hot caustic black metal finish. How accurate does it check out? Most of the better one's I know of are guaranteed to 50 millionths or better.
Anyone recognize this square, Bought it recently and cant figure out the maker/manufacturer.
