Dear Mr. Weasley, My name is Viktor Krum. My friend gave me your name and suggested I arrange a meeting with you. I would very much like to speak with you about a private club you belong to that I might apply for membership with. I have references, of a sort, and I am in the position to lend some assistance I hope.
I am at your disposal. I await your reply.
Sincerely, Viktor Krum
Dear Mr. Lupin, My name is Viktor Krum. This is the second owl I have sent, in the hopes of arranging a meeting with you. My friend gave me your name, and thought I could lend you some assistance. If it would be possible to meet, I would greatly appreciate the chance to find a different diversion to my currently occupied time.
I am at your disposal. I await your reply, in the hopes that this owl finds you.