What is the ruling on a paternal uncle attributing to himself actions performed by the father, such as supporting his family and marrying off his sisters?

Whoever attributes to himself good qualities he does not possess, or claims virtues he does not have, lies to himself and to people. Allah Almighty says: (Do not think that those who exult in what they have done and love to be praised for what they did not do—do not think them safe from punishment, and for them is a painful punishment.) Aal-Imran/188. And "one who claims to have been given what he has not been given is like one who wears two garments of falsehood," meaning one who feigns possessing virtues he does not have, in order to gain more esteem among people. And whoever makes a false claim to gain more, Allah will only decrease him. This should not sadden you or your father, because the believer spends and gives for the sake of Allah, and Allah does not let even an atom's weight go to waste.