The Eterna calibre 520 is a superb pre 1950’s movement and their last model featured modern shock protection. This watch is in decent condition, but in need of a service.

The movement is in decent condition. (I have already replaced the barrel bush when I did my last 520).

After cleaning the movement I fit the cap jewels to see that the movement moves freely. I like this version the best as it provides the best shock protection.
6 Responses to Service Eterna 520U
Hi Mitka,
Great walkthrough! Thank you for sharing. Question, did you have the case replated?
Gary
Hi Garry,
No need as it’s stainless steel. The discolouration on the case was grime that cleaned up:)
Best regards,
Mitka
Hi Mitka,
Great articles on your site. I wish you all the luck now that you are working independently.
One question, how do you know this watch should have a crystal without a tension ring?
Regards
Hi Dušan,
Thanks:)
You can tell by the grove the crystal is fitted in. Tension ringed crystals have straight edges while the normal crystals have a slant grove.
Best regards,
Mitka
Excellent site & information & first class work.
Thanks for the kind words David:)