These are interesting pliers not withstanding the odd shape. They were made for adjusting the Steedraulic brakes on cars built in the 20's and'30's. If you Google Steeldraulic brakes you'll learn more than you ever wanted to know about them. They were made by several manufacturer's back in the day. The Cornwell's I found at a local flea market for $5.00...so they followed me home. Then about a week or two later I found the VaccumGrip pair at another flea market...these also followed me home. They are the only two I've ever seen in quite a few years of haunting flea markets, auctions, and garage sales.
I lifted this from the AA site. "In the late 1920s and early 1930s several makes of automobiles (e.g. Hupmobile, Auburn) were equipped with Steeldraulic brakes, a brand of mechanical brakes with an odd adjusting mechanism. Special pliers were required for making adjustments to these brakes, and not surprisingly the pliers came to be known as Steeldraulic pliers."
Mike