 Due to the immaturity of the twin-hole style early on, some twin-hole guitars were returned to the GLW for repair, ostensibly due to distorted tops (sound board) as a result of insufficient bracing under the bridge.In addition to guitars, specialty instruments produced at the GLW included lute, vihuela, and viola da gamba.At least one of Eddie Kamae's ukuleles was built at the GLW by Brian Ikehara.