There's also the Han Solo trilogy of novels and the Han Solo and Lando Adventures trilogies which explore Han, Lando and Chewie's past in detail and with better pacing and characters than those of the Disney Solo movie. It has a few inconsistencies caused by the prequels, but since you're an OT purist that shouldn't be an issue thankfully. There's also the Corellian Trilogy set 16 years after the OT and deals heavily with Han's homeworld.
Aside from these, the other Star Wars RPG guides, sourcebooks and campaign guides are worth a read if you're interested in reading about the galaxy's societies, cultures and technology. The Dark Stryder campaign is a real doozy.
I know you aren't a fan of the prequels, and its perfectly understandable why, but some of their tie-ins (mostly the ones focusing on Obi-Wan, Qui-Gon and other jedi and several other characters) are actually worth giving a shot, so if you want a less divisive version of the PT you could give the prequel novelizations a shot and see if they do anything for you with their more detailed events and better pacing, since even people I know who hate the prequels prefer the novels to the films. Its not 100% guaranteed though since it still has the same endings, the same clone war and timeline issues as the films and Anakin going insane, however it does add more details about Anakin's declining psyche. The most acclaimed PT novel though is Darth Plagueis, which explores Palpatine's life and rise to power as well as the life of his master who influenced many of the PT's events. Some PT novels and guides also try to correct the inconsistencies caused by the films, and some comics even openly poke fun at them too, showing that George was more than willing to let his content creators take friendly jabs at him unlike Disney.
If you're still interested after all that, I could give you more suggestions (there's no shortage of stories taking place across different periods), or even suggestions to material that takes place long before the OT like the Tales of the Jedi comics which are a must for some in-depth jedi and sith lore and tie-in to KOTOR. There's also the Young Jedi Knights series, which is mostly aimed at kids so its not something amazing, but it introduces you to Han and Leia's kids who play a bigger part in future stories and many elements from those books show up elsewhere. The books also introduce the hilariously well-aged villains known as the Diversity Alliance. After all that and more, you could also try the NJO series if you like grimderp and want to know what's going on in the galaxy 30 years after the OT. Could be hit or miss though. Its a very well written series but some elements from it can be off putting newcomers (like spoilers:
Chewbacca's death, religious fanatics from Hellraiser resistant to the Force, unnecessary mass destruction on a wide scale that shrinks down the setting, a talking planet, killing off or setting up the fall of next generation of characters for no reason, pushing R2 and 3PO to the side even more, and a crazy grey jedi bitch spouting bullshit as fact and who needed a good punch in the beak from someone), and its mostly a character driven series of stories that doesn't put much focus on the setting of the planets themselves (and has several inconsistencies lore wise in regards to certain species and planets), but its a very mature series that you'll either love unconditionally for its writing or find that its not to your tastes due to its decisions or that it diverges too much from the saga's views on good and evil. It all depends really like 50/50, but most agree that its a better alternative to the Disney trilogy, even if I only slightly prefer NJO over Disney. There's also the Legacy comics and Sourcebook which take place 140 years after the OT and shows what Luke, Han and Leia's descendants are up to and how his Jedi Order has come along in the future. Its starts off great, but near the end the series starts getting rushed and only its sourcebook really bothers to fill in the blanks. Also pretty mature but has been a 50/50 thing too. I personally like it. However Legacy and NJO are something that should probably be read after familiarizing yourself with the rest of the setting since they heavily reference a lot of things that came before them and aren't as self-contained as other stories, and events from NJO are a major factor for two catalysts in this comic.
