First of all, welcome on the forum!
I've quickly scanned your tree, and I may have a relative of Scrooge that you still miss. In Zio Paperone e il risparmio controproducente Qui, Quo and Qua find an old painting in the dumping ground. After cleaning they read a name, Adolphus Mortimer de' Paperoni. Paperino says that this one is a "distant relative" of Paperone. He refuse to buy the painting, but later regrets it, because the frame is full of money.
Another relative is from Fun Director. Scrooge looks at a distorcing mirror and says he looks like cousin Fatso. Strangely the italian translation makes no mention of him, but looking at another mirror PdP says he looks like his skinny cousin Menelao.
Adolphus Mortimer is already on the tree - he's Quagmire McDuck's grandson and Scrooge McDuck's second cousin!
However, Scrooge's cousin Fatso is new to me! I'll add him in the next update!