All this about the OSR is one reason I love Classic Traveller 1977. It's very old-school design in the "rulings not rules" sense, but holy Spaceballs would it benefit from some OSR-style graphic and information design. I'm not as familiar with the Cepheus Engine stuff, but I'd be surprised if there weren't a few that modeled their stuff after that kind of visual design.
I own 5 different flavors of Cepheus Engine and the approach to graphic design varies a lot. I will say, none of them have the production quality of Mongoose Traveler 1e, which the CE SRD is based upon. Of those 5, for the 3 that are close to the MGT1E/CE SRD, Stellegama Publishing's Cepheus Deluxe would be closest to an "OSR-style graphic and information design" - OSR style graphics definitely seems to be an influencing factor. While Moon Toad Publishings CE crb is devoid of any graphics whatsoever with a very utilitarian design, but remains my favorite flavor due to the quality writing, good organization and adhering closer to the SRD. Zozer's Hostile Rules crb -a CE edition tailored to their terrific Hostile setting- would be the closest to a more modern graphic and design style.
That said, they all to some extent have a fan-made, done-on-a-budget look to them - Hostile being lesser so than the other 2.
Although TV and movies, it's reversed. Fantasy is the unpopular one, and sci-fi rules supreme (LotR and Game of Thrones notwithstanding).
I was a kid in the 60's and became a young adult at the close of the 70's. I can say the Fantasy genre was very much overshadowed by SciFi at that time. For TV we had original Star Trek on every day, Battletar Gallactica and Space 1999. At the theatre we had 2001, the return of Star Trek in 79 and of course the blockbuster Star Wars in 77. There was Planet of the Apes at the theater too, but you could argue it was SciFi as much as Fantasy - I consider it Fantasy SciFi. Even for novels, while there was some well-selling Fantasy series like the Conan continuations, Narnia and LotR, there was far more SciFi. Other than the Ray Harryhausen Sinbad movies, I can't recall much memorable Fantasy at the cinema. Albeit, Burrough's Tarzan was popular for saturday matinees.
As a teen in the 70s, I was craving and asking about anything Fantasy or SciFi. Despite having some quality bookstores in my city that stocked a dizzying number of pocket books, I never had Vance's Dying Earth, Borough's Pellucidar, Norton's Witch World, Lieber's Fafhrd & Gray Mouser or Morcock's Elric pointed out to me. I did however have Azimov's Foundation trilogy, Niven's Ringworld, Herbert's Dune and Clarke's many novels recommended. Martin's GoT, Cook's Black Company and Thieves World, among many other quality Fantasy series, hadn't arrived yet. There's no arguing LotR was a block buster - many folks had the unlicensed Ace Publishing print, it got lent around and it often came up in conversations. It wasn't that old though, having only been published in the late 60s and The Silmarillion which came out in the late 70s disappointed many fans - personally, I ate it up.
I actually think the sucess of D&D was in part due to the lack of the Fantasy genre in the different media. While not a novel series, a TV show (least not until 83), or movie, it still filled a void for a genre that was lacking. It also wasn't all that clear in the late 70s that it wasn't based upon LotR - first time I sat down to an AD&D table I just assumed with elves, dwarves, rangers and dungeons that sounded like Moria, that it was about Middle Earth. Then there was the demonic hysteria around D&D in the mid 80s, which at least in my area did nothing but make it more popular. In my recollections, it was the 80s that was the big decade for Fantasy, as we had Excalibur, Conan, lots of Sword & Sorcery movies and many new novel series.
That a SciFi based TTRPG like Traveler didn't share the same success as a Fantasy one is somewhat perplexing to me, considering the popularity of SciFi when it debuted. On the other hand, it had a lot of other SciFi media to compete against. I didn't encounter Traveler until the mid 80s, despite being a regular player at a college gaming club that had TTRPG tables. And even then it was in a campaign that mixed AD&D1e with Gamma World and CT - yes our club had some GMs with weird ideas, but thankfully the skill to pull them off.
Anyhow...didn't want to side track to much. Traveler has been a bit there, then and now for me. Having 1st encountered it at the above mentioned club, but then not experiencng it again until the early 90s. At that 90s session a player died during PC creation and I wondered if it really was a RPG for me. I really came to regular Traveler player play due to my disappointment with the Battletech RPG - A Time of War. One of my players mentioned that Traveler was similar - also claimed it was inspired by Traveler.
So...with Mongoose Traveler 1 being the current edition then, I browsed the book, bought it and it's the edition I've run and played the most. I've since moved on to MGT2E. I've mostly homebrewed in the Foreven Sector of the Traveler verse, with campaigns featuring heavy metal like Mechs in ground-based action and lots of courtly intrigue and politics like the Battletech verse. That hasn't proven to be so easy though and I arrived at a point where Traveler and it's 3rd Imperium setting and focus didn't seem like a very good fit. Cepheus Engine on the other hand, with it's massive library of 3rd party companions and supplements has proven well suited to it and its what I now use the most.