The long pair is marked Cin. While the shorter pairis marked C.
I believe the twocompanies are the same just used different markings at different times. There is also an H with a circle around it oneach of the clamps. This owner of the company and designer of the clamps was named Hargrave. They are in very good condition.The item "4 Vintage Antique Woodworking Clamps C. Hargrave Pickup in CT" is in sale since Wednesday, September 12, 2018. This item is in the category "Collectibles\Tools, Hardware & Locks\Tools\Other Collectible Tools". The seller is "ctyankee48" and is located in Suffield, Connecticut. This item can't be shipped, the buyer must pick up the item.