Revealing mistake: When Alfalfa is running in the street only in his underwear and socks, it is very obvious that he has sneakers under his socks.
Revealing mistake: When Spanky and Stymie are going into the bank for a loan, it's clear that their legs are that of an adult based on how high up the knees are. This is even more apparent when they are leaving the bank, in that their knees are at the same height as the adults going in.
Revealing mistake: When Alfalfa is being chased in his underwear, watch the cars on the bridge. They are going way too fast, showing the scene has been sped up.
Answer: Because MGM owned the rights to the "Our Gang" trademark, when the early films were re-released and new series started, the name was switched to "The Little Rascals" (for example, the 1982 cartoon) and that's what most people know them by. After that, it gets tricky with which companies own which rights, and King World Productions has some of "The Little Rascals" distribution rights.
Bishop73