According to one poster on The Garage Journal:

The anchor vise company was in business from 1973-2004 and made 5 different vises a 4,4.5, 5, 6, 610 and a few smaller vises along with assorted specialty tools. They sold to mainly the US government. You will see the large No.5 vise on the military M35A2 troop carrier and wrecker trucks used by the US Army. All of the vises and tooling was sold to RCI Starlite International in Bridgeport CT.