Serial number 204925 was stamped on September 28, 1965 and cleared final inspection on Novembr 22 that year.
The tuners are Waverly G-13 (or possibly G-31) machines with white celluloid buttons.
Style 21 features:
Back and sides: Brazilian rosewood
Top: Sitka spruce
Binding: Tortoiseshell celluloid
Backstripe: "Zipper" purfling pattern
Other period features:
Brazilian rosewood fingerboard
Brazilian rosewood straight bridge
Steel T-bar neck reinforcement
No pick guard
No fingerboard inlays
Decal on front of headstock
No C. F. Martin stamp on back of headstock
Photos courtesy of Schoenberg Guitars