There's a short Italian man that is featured at the wedding along with the singers. He also apparently works for Don Vito at the Genco Olive Oil Company as he is the one who helps the Don with his coat before he leaves the building before the assassination attempt.
Vito says "Buon natal, Caro. Grazie" as he is helped with his coat, which roughly translates to Merry Christmas, Caro. Thanks.
I can find no mention of the actor who played "Caro" or the character's full name. Anyone have a clue to this mystery?