I have aged this one myself many times with Ammonia. They come shiny and golden coloured. They will naturally Patina if you leave them alone too.  Here is a copy of a post I made about one of the Patina journeys.  A Beonzo journey:

It had patina




Patina removed by soaking in lemon juice.



Dipped in salt water before new patina.



Placed into a tub with ammonia, Bottle cap used to keep the watch out of direct contact with the ammonia. Then sealed for about 10 minutes.




The result



Cleaning it up
















On the wrist






Cleaned lightly with a toothbrush and lemon juice to return it back to a light copper look.



  So after a few weeks it darkens and starts to look like the shot I posted above.       
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