The Addams Family: Lurch and His Harpsichord (1965) (TV)

Synopsis [spoilers]: A museum curator is passing by the Addams' residence when he hears the sound of the harpsichord; he stops and knocks at the door. They let him in, and he tells them how fascinated he became with their harpsichord; he only regrets that the museum can't afford to make an offer for it; Gomez, in a generosity fit, donates the harpsichord to the museum; he only asks for a couple of days to make Lurch accept the idea. Lurch is much more affected by the loss of his dear harpsichord than they ever imagined. They decide to build him a new one. They lie to him though: they say they stepped back from the donation decision, and that the harpsichord made by them is really his old one. However, the guys from the museum come to fetch the harpsichord a day earlier than scheduled, when Lurch is alone in the house. They take the Addams-made harpsichord instead of the old one; Lurch thinks he was betrayed, and that he lost his instrument once again, and for good. He packs to leave, but is stopped short by the arrival of the Addams. They talk him out of the idea of leaving. A phone call arrives: the so-called curator was in fact a crook who tried to sell the harpsichord to the museum; since it wasn't a legitimate Krupnik, he was arrested. Gomez declares that it was fate, and decides to keep the old harpsichord after all, much to Lurch's contentment. Gomez says he is defending the phony curator in court, and Morticia is glad: she thinks he deserves a life sentence.

Saw it dubbed in Portuguese.