You are sincerely on the right. Sincerely yours is at the top of the signature, and the signature is generally signed in the right middle position below the conclusion. The signature should be handwritten, even if it is a letter typed by typewriter, it should be signed in the end. Sincere Yours/ Yours (to elders or friends) can be written on the top of the signature according to the relationship between the writer and the recipient. Or respectfully your/ yours (for elders or superiors). So sincerely you are on the right!