Serial number 73066 was stamped on August 10, 1939 and cleared final inspection on November 6 that year.

The tuners are Grover pointed plate G-98 machines with unseamed butterbean buttons.

Style 18 features:

Back and sides: Mahogany

Top: Red spruce (Adirondack)

Purfling: Lines

Binding: Black celluloid

Other period features:

Rear-X scalloped braces

Ebony fingerboard

Ebony belly bridge

Steel T-bar neck reinforcement

1-11/16" neck width at nut

Tortoiseshell celluloid pick guard

Dot fingerboard inlays

Decal on front of headstock

No C. F. Martin stamp on back of headstock

Style stamp

At the time of writing this guitar is available at Elderly Instruments (https://www.elderly.com/collections/category_acoustic-guitars/products/martin-d-18-1939)