I have the privilege of attending Solemn High Masses in the pre-1955 rites every day of Holy Week.
So, being the curious man I am (curious as in inquisitive amid the world around me and not odd), I did a little research.
You’re welcome in advance.
https://www.newliturgicalmovement.org/2009/03/use-history-and-development-of-planeta.html?m=1
Harvey Millican's Blog: Musings of a Trad Dad 