When Moritica takes the jackhammer from Gomez, it starts without her flipping the switch. The same thing happens when Fester takes it.
The large stuffed bear is brown during the fencing scene (due to recycled footage), but white in the trampoline scene.
Obvious cuts between close-ups of Gomez bouncing up by the chandelier.
When Morticia collects her love letters, the back envelope falls and the address is shown right side up. When the camera zooms in on the envelope, the address appears upside down.
Re-used footage taken from Crisis in the Addams Family (1965) of Gomez and Morticia playing Badminton and from The Addams Family Tree (1964) of Morticia and Gomez fencing has clearly been re-dubbed with a references to Pugsley falling in love with his teacher. Morticia's lip movements bear no resemblance to the words being spoken.
Morticia says she'd like to show Pugsley some of the love letters Gomez wrote her while they were courting, but in Morticia's Romance: Part 1 (1965)/Morticia's Romance: Part 2 (1965) there was no courting. Morticia & Gomez' marriage came suddenly and immediately, right after Ophelia, to whom Gomez was supposed to wed via an arranged marriage, left him at the altar to run off with Cousin Itt.