Gibson MK-53, 1976, naturalBetween 1975 and 1978, Gibson worked with Dr. Michael Kasha’s applied acoustic theories for guitar and Luthier Richard Schneider design applications to create a unique instrument for the Gibson acoustic lineup. The Mark Series guitars have 16 3/16″ lower bouts and narrow waists, and a headstock like no other in Gibson tradition. The instruments have modified fan bracing and asymmetrical bridges. Ironically, the script logo on the headstock is old-style Gibson script.Each model of the Mark Series was available in natural finish or sunburst. The selected tuners varied by model and year.MK-53 models are maple back & sides, rosewood fingerboards with dot inlays & nickel hardware.