The museum pieces were often serviced, by Omega, to the standards upheld at the time the work was done, many years ago . This means that bezels, dials and hands were replaced with contemporary ones that now look "wrong" to people who want a watch that looked the same as when it left the factory, not carrying parts that it acquired 10 or 20 years after it was built.
The Astronaut watches also show this trait. Understandably as NASA wanted the highest quality machine, and often that meant replacing parts that we collectors would want to keep, in spite of the wear or defects that would reduce performance in extreme conditions.
This is why referring to these museum pieces hoping to get a definitive reference as to what was fitted when new, is most unreliable.
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