Where Do You Source Watch Parts?

I'm curious about where watchmakers and repairers usually source their parts.

Do you have a preferred supplier, or do you use a mix of genuine and generic parts depending on the job?

gizmo wrote:

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Someone who is taking their business serious will not give you information on this without fully knowing you or have not help them in some way,

Because if they said they will basically give another person their business.

Don't get me wrong some people out their will tell you but its really hard to find that person without giving them something return even its a solid piece of advice that benefit them in some way shape of form.