The used Rolex watch market is robust and maybe even a bit crowded. Why? Because pre-owned Rolex watches are big business given the fact that Rolex watches have such an incredible ability to retain value. Still, it is sometimes hard to justify buying an older model when new models exist. One good way to breathe life into older, good condition Rolex watches is to modify or customize them. That way you aren't one of legions of people who have the exact same Rolex watch. Rolex modification is a gro...