From Martin:

Here to remind you why you fell in love with us in the first place, the new Authentics are constructed the old way – with hide glue, throughout, and historically-accurate detailing confirmed by using a CAT scan machine located at the Smithsonian Institute. Based on a 1939 D-18 in our museum, this guitar features genuine mahogany back and sides, an Adirondack spruce top, using an authentic circa 1939 bracing pattern. Period-correct “18” Authentic-style appointments, with an Authentic neck barrel and heel, complete this piece. Martins new Vintage Tone System (VTS) is employed for the top and braces.

The new Martin Vintage Tone System (VTS) uses a unique recipe that is based on the historic torrefaction system. The VTS acts much like a time machine in which Martin can target certain time periods and age the top/braces to that era. This focused method allows Martins craftsmen and women to recreate not only the pleasing visual aesthetics of a vintage guitar, but also reproduce the special tones previously reserved for vintage instruments.

Vintage Gloss Natural, D-14 Fret body size, Solid Adirondack Spruce top w/VTS, Authentic 1939 rear shifted Adirondack Spruce w/VTS scalloped X bracing, Old Style 18 multi-stripe Rosette, Faux Tortoise binding with the multi-stripe top inlay, Solid Mahogany back and sides, Madagascar Rosewood back purfling, Ebony fingerboard with the Old Style 18 Abalone position markers on an Authentic 1939 w/standard taper shaped Mahogany neck, 25.4 scale length, 1 11/16th width at the nut, With hardshell case