Maybe nice idea to read up on your Constellations: see this link http://omega-constellation-collectors.blogspot.com/ You will probably learn to avoid this particular piece, sorry.
From what I can tell from this read: http://users.tpg.com.au/mondodec//Counterfeit_Omega_Constellation_Cases.pdf - hands are inconsistent with the hour markers - facetting of the lugs (both sides) is missing - star and 'Constellation' are too close - star is not in line perfect - photo's show the bezel not very clearly, but seems too rounded instead facetted I might recommend everyone who is enthousiastic about the Constellation to read and enjoy the Constellation Collectors Blogspot! It is a well written site with an enormous (as in 'huge') amount of facts, pictures, in-depth knowledge which is evolving still!