Fairly unusual to see one on a #51 I would have thought?Sometimes, you'll find a plane with a hard rubber tote with "B of E" embossed on each side. These were sold by Stanley to school systems as replacement totes for the poor planes that suffered the onslaught of destruction as wrought by the punks of yesteryear. "B of E" stands for Board of Education. These replacement totes were offered during the 1910's-1920's, when they were replaced with aluminum totes during the early 1930's. The replacement totes are most often found on the jack planes since they were the commonly used planes in the school systems across the USofA.