It’s important to keep in mind that before 1984, the ratings system was completely different. G meant for kids, PG meant for teenagers (kids aren’t recommended), R meant for adults (kids aren’t allowed without parental permission), and X meant kids aren’t allowed whatsoever under any circumstances (usually porn, but not always).

PG-13 not only didn’t exist, but PG of the time was definitely harder than PG-13 of today, and while the Original Trilogy wouldn’t be considered R today, a lot of PG movies of the 80s would be considered R today (especially horror movies, which is what prompted the redesign of the ratings system, people thought PG meant okay for kids when it did not). Additionally, I’m pretty sure all three OT movies would get PG-13, and maybe my hatred for American puritanism exaggerates this in my mind, but I’d imagine RotJ might push it with Slave Leia. All three of them are harder than anything in the sequels or prequels.