While I know te dial is in bad condition an clearly the date wheel has been replaced, I am confused by te inside caseback.
OMEGA CONSTELLATION CHRONOMETER 18K Funcy lugs: http://www.ebay.com.au/itm/221216887781#ht_500wt_1414Purchases made through these links may earn this site a commission from the eBay Partner Network

 

That's certainly not a Bienne made case. The lugs look really weird from the side. What's with that extra curl?

 

South America or South Africa case? The lugs certainly looks unusual. the rest looks original (while not in good condition).

 

Canberra has mentioned that the date wheel has been replaced........

 

I think the case is counterfeit.

The stars are way to big, the hallmarks are weird and the markings and finish inside the case back are also highly suspect, that Omega mark is way to early for this and only the very earliest Constellation cases had a perlage finish inside (2648).

 

Could it be Franken rather than fake? The caseback looks right for a much earlier watch. Earlier symbol, serial number not model number. Then they hae somehow added a medallion after? There is a weird gold mark in the observatory also.....

 

Watch is in Turkey, which makes both of these less likely, but who knows,

 

Another thing, the seller notes in his description that the case is28k Rose Gold ! So it looks like it's made of pure gold with 4k for free, potential bargain for someone!

 

The more I see it, the more convince I think this is original example. Look at the medallion, while there is a ding, but the rest is very sharp. Looking at the caseback, this is not Bienne version. The datewheel is joker type (red and black), possibly a replacement, but if it is original made it uncommon. If the price is low enough, should be a decent purchase.

 

This is a strange one. Are you convinced it's original? I think the dial looks ok, but those lugs are really weird. I'd be interested to see if anyone had a similar example...

 

You have very keen eyes Lou, like the eagle........

 

So is this one 28k? I would think that too soft for watch?
Is the stamp on Obsevatory an Eagle?
Was this stamp on Observatory common for French
case? Common on other cases? Which?

 

From the listing "Case: 28k rose gold".

The case is marked 750 inside, 28k is just a mis-type on the sellers part.

 

From one of Desmond's blog posts showing this same "French" marking as being a counterfeit.

"Just when the fake Vietnamese/Chinese gold cases are having a sabbatical from various on-line auctions, their French-made cousins come along to spoil the show! These fake cases come in two varieties: pink and yellow 'gold' and one must use the word 'gold' advisedly.

It was not uncommon at all in the 1960s to encounter both French and Italian made fake Constellations. Most of these were fairly shoddy facsimiles containing non-jeweled movements and would now be fulfilling their true destiny: as landfill or metal scrap. But there were also some better versions where the cases appeared to be of a higher quality. Some of them may still be hanging around!

Above you will see two pictures. One is from a genuine Omega Between-the Two-Big-Wars silver pocketwatch. Notice the stamped Omega logo which was common from at least 1915 onwards. The second picture taken is of a fake case showing the old makers mark when it should show the newer makers mark that was consistent on most, if not all, postwar Omegas.

If you see a case back such as the above counterfeit example in an Omega Constellation of any period, know that it is not genuine!"

<edit Steve>
Desmonds's fake mark

The eBay watch