This guitar is a special order 1-18P guitar with a 5-string neck. Only two 5-string Martin guitars were ever made, this being the earlier example. The second 5-string, a 1-17PS, was made in 1939.
It will be noted that the guitar has a neck that joins the body at the 15th fret.
Serial number 38979 was ordered on July 1, 1929, was stamped on July 9, 1929 ans cleared final inspection on July 14. That's just 5 days in production! That has got to be the record!
Interestingly, this guitar was stamped one day before the first OM-28. Five-string guitar or 14-fret OM guitar, which will win?
The tuners are Grover #90 banjo pegs.
Style 18 features:
Back and sides: Mahogany
Top: Red spruce (Adirondack)
Other period features:
Ebony straight bridge
Dot fingerboard inlays
C. F. Martin stamp on back of headstock
No style stamp
Photos courtesy of Players Vintage Instruments.