You can start by introducing yourself, explaining how you are related to them, and how met. Possibly mention a few other relatives they may know to help break the ice. Then you can explain your reason for writing to them, giving them some examples of what you want to know and why. Always be polite, and respect their wishes. If they don't want to communicate with you, don't take it personally, but it is possible you may be able to reconnect with a family member.

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