Above, a wooden-handled screwdriver from my shop stamped with this manufacturer's name.
I've been unable to find out what the initials stood for, or when the company was founded, but they sold tools under their company name and also a "Blue Line" brand registered in 1961. Their products included chisels, punches, wrenches, screwdrivers and other tools. In 1980, they filed for bankruptcy protection, just after stiffing one of their wholesale customers with a batch of low quality wrenches. The company's trustee subsequently tried unsuccessfully to sue the wholesaler for the costs of the shoddy goods. Not a nice way for a company to go out.