This post is a bit of information about Omega watch crowns. It goes for any brand of watch.
A watch crown is a "disposable" part. It gets used and worn, it will need to be replaced when it is past it's service life. Failure to do so can easily end the service life of your watch. Here are some pictures of used crowns I have replaced. If I asked you to pick the best crown out of the lot, the center one would be the number one pick for sure.
Now I have flipped them over and you can see the best looking crown is by far the worst of the lot. The retainer ring and gasket are missing making it not only worthless, but it puts your watch at great risk of water damage.
I get this request all the time when I am servicing a watch, "Please leave the original crown."
Sorry, I cannot if the old crown will not do its job. An Omega Constellation would be better served with a new Bulova crown than a bad original Omega crown.
Here is a beautiful Seamaster Chronometer. Bad gasket in the crown caused quite a bit of water damage. Trust me, you don't want this to happen to your watch! This will run up the repair cost by the time I get done. Many parts cannot be saved and will cost far more than the new crown it should have had. Below is another picture of a movement that came out of a watch with a bad crown.
When I shop for watches I disregard the disposable parts; crown, crystal and band. All can be easily changed. Being a watchmaker the first thing I do when I get a watch is check to see the condition of the crown if I am going to wear it. I recommend you do the same or have your watchmaker check it out.
Omega and other brands have discontinued many models of crowns. Most can still be found with an on-line hunt. It is nice to have an original style crown on a watch. However, an aftermarket crown is just fine while you are hunting for an original.