| Caliber 641 (640) - Factory R Gruen Guild [message #12084] |
Sat, 01 February 2020 04:08  |
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Case
Messages: 1178
Registered: May 2019
Location: Cincinnati
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Gruen Authority |
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This caliber appears to have been introduced in 1922, possibly even late 1922. They have pre-1922 tariff markings, but there was a grace period. It’s the only Factory R stamped caliber I’ve seen yet, and the timing would make it one of the later “Factory X” stamps to come into use. But I do find evidence Factory R may have been a Gruen supplier earlier, just didn’t have or use the stamp until 1922. Perhaps a renaming/reorganization—remains to be seen.
These are stamped “640” between plates by the dial screw. All examples I’ve seen are the hunter variant, all marked “641” on the dial back. So they’re stamped for the base 640 open face caliber, the 641 the hunter variant.
Dials are made by Singer SA, all dials bear “107” stamp, which I believe could be Singer’s customer number/reference for Factory R. “107” appears on other much larger Singer dials at this time, too—like the 650. Hope to share an example soon.
Example 1:
Sn (front plate): 11454 (also has a partial “2” stamped to one side)
Markings: 15 jewels, 2 adj. (#s only)
My two caveats:
1) I'm wrong many times a day --just ask my wife!
2) Always seeking to learn more
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