Seaborg
·It's a question that baffled Omega Speedmaster Spaceflight fans for decades and Omega came out with the info as they had re-released the classic & iconic no crown guards Speedmaster with 321 movement...
One last note... the only photos I have seen on the subject of the destructive NASA testing of the wristwatches, are no TEST photos but more probably MAINTENANCE photos as the Speedmasters shown are clearly "Professional" dial with crown guards 105.012 versions
( 1968 NASA photos ? ).
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It's even a 105.012-66 CB 😁