Martin Custom Shop D Dreadnought Acoustic Guitar, 18 Style, Bearclaw Sitka Spruce Top with Sinker Mahogany Back and SidesThe Dreadnought has long been a cornerstone in the Martin legacy, a lineage that dates back to the early 20th century. With an 18 style touch, this Martin Custom Shop D Dreadnought 18 Style is a custom creation that pays some respect to a rich history, with the same resonance and tone that's made Martin's Dreadnought a staple. This custom guitar is built with a sinker mahogany back and sides salvaged from underwater, and a Sitka spruce top featuring