Martin made the 14-fret Ochestra Model (OM) guitars from 1929 to the end of 1933. Beginning in 1934 the OM designation was dropped and these guitars reverted to the 000 designation.
However, for a time in 1934 continued to use long scale (25.4") necks on 000-18 guitars. In effect, these can be considered OM guitars. The switch to the 24.9" scale length also coinincided with the change from the ebony neck reinforcement and bar frets to the steel T-bar and T-frets. Of the three hundred and twenty-five 000-18 guitars made in 1934, a total of 275 had the long scale necks (with ebony neck reinforcement and bar frets).
A small amount of steel T-bars were purchased prior to the first production order so a few earlier OM-18 guitars may be encountered with the T-bar.
Serial number 56808 was stamped on June 28, 1934 and cleared final inspection on October 25 that year.
The tuners are Grover G-98 clipped plate tuners with seamed butterbean buttons.
Style 18 features:
Back and sides: Mahogany
Top: Red spruce (Adirondack)
Binding: Black celluloid
Other period features:
Graduated dot fingerboard inlays
Ebony belly bridge
C. F. Martin & Co. stamp on back of headstock
C. F. Martin & Co. decal on headstock
At the time of writing (April 10, 2019) this guitar is available at Schoenberg Guitars (http://www.om28.com/ProductDetail?product=P140401002)
Photos courtesy of Schoenberg Guitars.