I find it odd that the Omega-trained technician who inspected the watch recently has stated that the wrong crown was fitted 3 years ago by an Omega dealer. I would hope to get some clarification on whether his statement is correct, and if it is, how this mistake could have happened.
Regarding
Reference number as Jim mentioned - 595.0099
One on Ebay. No sold models. Some ask high and some low based on similar designs
Maybe ask the wife if she would like something new. Sometimes repairing older watches just isn't worth the time and money
I don’t think we can provide any clarification on this over the internet. You should probably ask the people who did the previous repair.
Also, when a repair person tells you that the watch experienced water intrusion and a hard fall, they probably have a reason to draw those conclusions. I’m sure your wife feels that she is careful with her watch, but all it takes is one careless moment or an accident. It happens to everyone.
Not knowledgeable about Omegas, but I can attest as a lady there are many things a cautious and careful lady can do to a watch without realizing its potential for harm, such as:
1/ spraying perfume on wrist (which can be done on a daily basis) while wearing watch;
2/ applying handcream while she’s wearing her watch.
Both those daily activities are hazardous to a watch (with risk of ingress through crown) if the watch is used and no longer water resistant.
If the change of the crown was not done properly, again risk factor.
As for the crown change, I would expect cost of no more than 50 euros incl parts and labor from a good independent in my country—
good Omega certified watchmakers in the UK have been recommended on the forum.