I was recently given this Omega Automatic Chronometer Constellation. Anyone know what model number it is?

Also: how does one open up the back case?

Any and all information on this timepiece is greatly appteciated!

 

Hi Carl,

You open the case back either using a tool that fits into the notches, or (safer) a small rubber inflatable ball.

If you're unsure, best bet is to get a competent watch maker to do it for you, although at least with the rubber ball method, you won't scratch the back!

Looking at how much gunk there is around the edge of the case back though, you're going to want to have wiped that away first, or it's going to drop into the movement.

A tooth pick is a good tool to use for that job... No cleaning fluids/scrubbing brushes please!

Once the back is off you'll have the watch number, and be able to google exactly what you have.

A google image search for omega constellation might help you in the short term though.

All the best

Chris

 

Thank you very much for the tips, Chris.

I was contemplating using dish-soap and an old toothbrush to get all that grime off. Its stuck on there pretty good. Any thoughts on that?

 

Also: what are thise tools called and how much are they? What kind of rubber ball (could you post an example?)

 

useful guide here:

http://blog.esslinger.com/how-to-open-a-screw-down-watch-case-back-with-a-case-opener-ball/

They get sold as "case opening balls" for £££, or you can get a kids rubber ball for £.

Best to not use anything wet... As you don't know how watertight the case is.

 

So ... dampening a soft brush with alcohol is a bad idea.

I've already gone off using such a method for watch cleaning, but "It will bypass all the seals ..." could explain why the Omega Deville with 620 movement went haywire after cleaning this way a few years back.

It's all mended now and my son wears it.

 

Thank you all for your support!

 

Okay, so now I've removed all the grime on the front side of the watch using a toothpick (great tip, that one)

But I really need to remove the wrist band to get the rest of the gunk out smoothly. Anyone got a desription on how to access the pin between the lugs?

 

You need a specific tool for that.

BERGEON 6767-F is very good - rrp is £20 ish, but you can get them for less - https://www.amazon.co.uk/BERGEON-6767-F-Spring-Bracelet-Removal/dp/B001IZT8R2

Or you may be able to undo the clasp instead, and lay the bracelet either side of the head.

You can sometimes do this using a pin/toothpick.

 

I doubt if there is a clasp on that bracelet, it looks like it is a Fixoflez/Spiedel type. The best thing to do after you have removed it is either throw the bracelet away or keep it in a drawer. They have a nasty habit of chewing up the inside of the lugs - especially on gold plated watches.

 

Your watch looks like it is in a nice condition. You have got advice. I just link to this - as a warning from me...
https://omegaforums.net/threads/a-warning-you-morons-and-do-it-yourselfers.37759/

 

My qualified guess is ref. 168.017.