WWII Hamilton Model 21 Marine Chronometer and 15 similar items

This listing is for an authentic Hamilton Model 21 Marine Chronometer assembly, serial number N8540, complete with its official military aluminum transport canister. This timepiece features a documentable service history spanning from World War II through the late Cold War era. Production records for this serial range map to late 1943 Navy contracts. A physical military overhaul label attached to the chrome bezel explicitly reads: "# 8540 Overhaul Due Aug 1990." This label confirms the chronometer remained actively cataloged, maintained, and periodically re-serviced in U.S. military inventory through the late 1980s. The U.S. Navy maintained these mechanical systems during this era as a secure celestial navigation backup to electronic systems. While individual ship assignments are unrecorded due to lost historical paperwork, general service logs for this model series are archived within the U.S. Naval Observatory records. The chain-driven fusee movement is clean and completely free of corrosion. It features original Geneva striping across the bridge plates with crisp text markings reading: "Model 21, 14 Jewels, Hamilton Watch Co., Lancaster, PENNA." The alignment pillars are perfectly straight, and the helical hairspring is uniform. The central Y-shaped mechanical balance brake is fully engaged, holding the balance wheel static. This protects the fragile detent escapement components and balance pivots from shock and movement during shipping. The engraved silvered dial is clean with minimal aging, displaying the encircled (N) Navy stamp and 1941 design date. All four original black hands are present and properly mounted: the spade hour and minute hands, the Up/Down wind indicator pointer at 12 o'clock, and the sub-seconds pointer at 6 o'clock. The clock is contained within its original solid brass bowl casing with an intact glass crystal and side gimbal mount brackets. Includes the heavy-duty military aluminum shipping container, the black neoprene rubber shock-isolation lining inside the canister is entirely intact and has not crumbled or deteriorated. To prevent damage to the spring detent escapement, the movement will remain securely locked under its factory balance brake arm. *** Please note, NO KEY**** I do not have the right size key to wind and test, so this is being sold AS IS, although it had been maintained up thru 1986-87.