This one is rather simple. The Leafs are the only one of the Original 6 teams to make a significant change to their uniform since 1964. If you don’t count the Hawks removing the CHICAGO BLACKHAWKS black circle around their logo, since 1950 when the Bruins brought in the spoked B.
Here is the mini poster.

On a somewhat related subject, maybe it’s time to change up the socks – which continue to match the striping of the 1928-33 jerseys.