Hi Alex,
You are rigth and an e-mail from Wolf-Erich says
Father: Salomon KOREF
Mother: Fanny nee GRATUM
(Wolf-Erich Eckstein e-mail 121230)
I have not looked inte the IKG scanned Traungsbuch at FamilySearch but www.genteam.at says
No. 66149 Year 1901 Numerative 21 Code 2 Volume Favoriten
Last Name Koref First Name Emil Parents/Annotation
Last Name Engel First Name Hermine
Best regards
Thomas