Pre-war thumbscrew. Thumbscrews, in conjunction with brackets an dresonator lugs hold the resonator to the banjo pot. Orville Gibson founded The Gibson Mandolin-Guitar Mfg. Co., Ltd in Kalamazoo, Michigan in 1902. Over the years the company has changed names and locations and today is known as Gibson Brands, Inc and is headquartered in Nashville, TN. The company is known for having made some of the finest banjos, mandolins and guitars.