Brazilian rosewood, in absolutely superb condition. This is a large guitar for those days, and is quite rare - you see mostly O's and smaller. The absence of back binding and a herringbone rosette determine the model 17 or 18, and the records don't list any 00-17's for 1907; mahogany on style 18s didn't come in until a couple years later. On close examination one notices some anomalies: the frets are T-frets, thus the fingerboard may have been replaced, though there's no evidence of it, other than the frets; the bridge is a slight variant from the standard pyramid, and there's evidence that it has been off.
Martin used several different pyramid styles, and recently I saw another 1907 with the same detailing (Thank you Jimmy Caldwell). The serial number tells us that this is the 40th guitar made in the year, with a total of only 398. We have done a full set-up, including a neck reset and new frets; it plays like a dream and takes light gauge steel strings with aplomb.