From the Martin Website:
The D-45S Authentic 1936 Aged is based on an extremely rare large body D-45 that was once displayed in the Martin museum. It features Brazilian rosewood back and sides, a pre-aged Adirondack spruce top, and period-correct Style 45 appointments, including gold tuners with hand-engraved butterbean knobs. A newly constructed masterpiece that looks and sounds like it’s been played for 80 years, the D-45S Authentic 1936 Aged includes all of the goodness instilled within Martin’s Authentic Series, like hide glue construction and hand-scalloped X-bracing. It also boasts the Vintage Tone System (VTS) that ages the wood to replicate the sound of a highly sought-after vintage Martin, both in tone and appearance.