![Perturbations and the act of observation: A Seiko 6139-8040 from November 1974 | Adventures in Amateur Watch Fettling Perturbations and the act of observation: A Seiko 6139-8040 from November 1974 | Adventures in Amateur Watch Fettling](https://adventuresinamateurwatchfettling.files.wordpress.com/2023/04/starting-point.jpg)
Perturbations and the act of observation: A Seiko 6139-8040 from November 1974 | Adventures in Amateur Watch Fettling
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Seiko 6139-8040 Speed-Timer Green Chronograph Automatic Cal... for $550 for sale from a Trusted Seller on Chrono24
![Seiko - Sports Speed-Timer Automatic Choronograph Men's Watch - 6139-8040 - Men - 1960-1969 at auction | LOT-ART Seiko - Sports Speed-Timer Automatic Choronograph Men's Watch - 6139-8040 - Men - 1960-1969 at auction | LOT-ART](https://gcp-la8-storage-cdn.lot-art.com/public/upl/81/Seiko-Sports-Speed-Timer-Automatic-Choronograph-Mens-Watch-6139-8040-Men-1960-1969_1591494939_6308.jpg)
Seiko - Sports Speed-Timer Automatic Choronograph Men's Watch - 6139-8040 - Men - 1960-1969 at auction | LOT-ART
FS: Seiko Blue 1976 Serviced Kanji JDM Automatic 6139-8040 Chronograph watch | WatchUSeek Watch Forums
![Perturbations and the act of observation: A Seiko 6139-8040 from November 1974 | Adventures in Amateur Watch Fettling Perturbations and the act of observation: A Seiko 6139-8040 from November 1974 | Adventures in Amateur Watch Fettling](https://adventuresinamateurwatchfettling.files.wordpress.com/2023/04/finished-1.jpg)
Perturbations and the act of observation: A Seiko 6139-8040 from November 1974 | Adventures in Amateur Watch Fettling
FS: Seiko Blue 1976 Serviced Kanji JDM Automatic 6139-8040 Chronograph watch | WatchUSeek Watch Forums
FS: Seiko Blue 1976 Serviced Kanji JDM Automatic 6139-8040 Chronograph watch | WatchUSeek Watch Forums
![GENUINE SEIKO 6139-8040 Automatic Chronograph Vintage skx pogue Jdm speedtimer EUR 599,00 - PicClick IT GENUINE SEIKO 6139-8040 Automatic Chronograph Vintage skx pogue Jdm speedtimer EUR 599,00 - PicClick IT](https://www.picclickimg.com/wtIAAOSwtgtj8LBp/Genuine-Seiko-6139-8040-Automatic-Chronograph-Vintage-skx-pogue.webp)