I have seen these wrenches called some different names like engineer's wrench , machinist wrench what ever , this one is a Billings . Because I'm all about the vintage , I love these things plus my little Atlas/Craftsman 6" has square nuts and bolts , so these are a natural .
http://www.ebay.com/itm/401078558496?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/401078558496?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT