Serial number 151874 was stamped on October 4, 1956 and cleared final inspection on January 23, 1957.
The tuners are Kluson K-500 "waffleback" machines with rounded metal buttons.
Style 28 features:
Back and sides: Brazilian rosewood
Top: Sitka spruce
Binding: White celluloid
Backstripe: Zipper pattern
Other period features:
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
Photos courtesy of Steve Swan Guitars