Changing the color or design of the dial is another common area of modification. Imagine you are disappointed when you find out that the 1965 blue watch that you just bought was only released in the black or silver version and your watch is greatly reduced in value because of the previous owner's wishes and preferences. You can sell rolex watch at a reputable watch shop to save more money.
The diamond bezel is another common addition. There was a time when Rolex only put a full diamond bezel on a valuable piece of metal. Only partial diamond bezels are permitted in two-tone editions and under no circumstances is diamond bezels produced on stainless steel pieces.
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This led to a large number of people paying independent jewelry to install a diamond bezel into a stainless steel Rolex. In some cases, as attractive as these additional features, this feature also completely removes the integrity of the watch. This also causes problems with warranty and all types of services by Rolex.
Existing companies only allow watchmakers who are certified by them to work on their watches to prevent unnecessary internal damage that might be caused by accident by untrained watchmakers who work their watches. I personally think this is really fair, after all the reasons why Rolex took the cost of repairs based on the warranty provisions for damage caused by untrained third parties?