A very interesting D18 this one. There are periods when Martin had quantities of "Different' Timbers than was normally used in their production. Their ledgers are considered meticulous and they can answer questions about a specific guitar. Historians studying these ledgers have discovered that in 1953 and 1957 in particular, through to 1962, there were very low numbers of guitars that were built with what have become known as "Mystery Tops", with the mystery being, what type of Spruce used. Some say "Adirondack "Red" Spruce, while others suggest "Engelmann" and "German Spruce. This D18 turns out to be from a batch of 25 guitars, 5 of which are recorded as having German Spruce Tops. This explains why the Top looks to have a different Spruce, it doesn't look like Sitka as per the specification, nor has it aged to the same colour that the Sitka guitars do. It is worth adding that it sounds warmer and has some different tonal complexities when compared to the Sitka Guitars. More important, it is a remarkably good guitar, totally factory original. From the period in the old North Street facility, when they still used Hot hide Glue when assembling their instruments. This one has a Brazilian Rosewood Fretboard, Bridge and headstock Overlay. Lovely Honduras Mahogany Back, Sides and Neck, Celluloid Tortoise Binding and Pickguard, "Thru" Saddle Bridge, Kluson Tuners, Small Maple Bridgeplate and all the goodies from its era. A beautiful sounding, extremely playable D18, ready to record or gig with.