VINTAGE DOUBLE OPEN END WRENCH

Any vintage (antique) wrench experts out there? I think its a Williams although it's not marked such, but it is marked "1140" on the side, and there are a lot of Williams with that number. I really don't understand what the symbols are. one end has "1, a hexagon, O, then 3/4 USS. But I measure that end to be 1 3/8" ? The other end has "5/8 USS", but I measure that end to be 1 1/16". ? There is a makers mark or something near the 1140 stamp. The wrench is 12" long, and quite thick. Any thoughts?