Serial number 45317 was stamped on December 31, 1930 and cleared final inspection on February 21, 1931.
Since it was made prior to March 1931 it retains the "small" pick guard and banjo tuners of the original OM guitars but has a belly bridge that became the norm in April 1930.
Typical for style 28 guitars it has herringbone purfling around the top and a zig-zag backstripe.
Grover #89 Deluxe banjo tuners were used on the original OM-28 guitars. However, the Grover #89 units were quite troublesome for Martin and many guitars were converted to side tuners as time went on.
Back and sides: Brazilian rosewood
Top: Red spruce (Adirondack)
Good as it gets…