Exceedingly rare Gibson K-4 mandocello, in its original hard case, and the only example we've had in our decades in the business with an adjustable truss rod; acquiring this very instrument was likely the impetus for John Bernunzio's journey to find the best vintage stringed instruments to begin with! A special instrument, with both thunderous and dynamic tonalities, with awesome playability, and a nice straight neck. Built in 1924 based on factory order number 11106 but not shipped until 1931, this example boasts a primo Loar-era improvement, the adjustable truss rod, lending itself well to the comfortable v-profiled three piece neck. The mammoth F style body is fully bound with high grade flamed maple sides with two piece back, carved spruce top with singular brace, rosette around oval sound hole of ivoroid and marquetry, with original tailpiece, adjustable bridge, and pickguard; inside original oval label is present, with FON stamp near end block; some normal top sinkage present. The three piece maple neck has a 24-3/4" scale length extended/fully bound ebony fingerboard with 1-7/16" wide fingerboard at nut, and with "The Gibson" inlaid in pearl, above flower pot; the thin frets appear to be slightly later and have very little wear, with a peghead curlicue reglue (small dowel) and later tuners. In fine original condition, we are noting light overspray or buffing having occurred (perhaps in the middle part of the last century), with normal amounts of finish checking, light play wear, dings, scuffs, and some binding shrinkage. Don't wait another 20 years for this one!