BobaFettSlave_1, That's one of the reasons I like to maintain the Boba was saw in ROTJ -- and thus, The Mandalorian and BoBF -- was an imposter, with an imposter ship. Jabba could afford it. That's also my justification as to why the current ship is "Boba Fett's Starship". The actual
Slave I is out there being flown by the actual Boba Fett in the ESB armor, sitting in the ESB cockpit. I appreciate that they at least didn't make the cockpit rotate, though the rotating interior makes as little sense. We've seen how highly-directional the GFFA's gravity fields are, and how smooth the transitions are between them. So the passengers would have been just fine sitting with their feet toward the engines and their heads in the direction of flight, while Boba was up there in the cockpit, sitting in a gravitational plane 90° off from that. They would all feel "down" pulling toward their respective "floor".
I know that by the mid-'90s, Lucas Licensing was working more actively to maintain continuity between ancillary material, and those with the films. Unfortunately, some of the earlier, pre-"EU" offerings had borked that latter requirement, and it was years of careful wording and massaging and certain-point-of-view to nudge things back toward filmic-agreement. Much of which started getting blown to hell when the Prequels started. George had said which
eras he didn't want people to touch, and made characters like Obi-Wan and Anakin off-limits to others, but he never put the kibosh on Han or Boba, so we had a lot of their early life and family sorted by the time AOTC (and, later, Solo) came along.
Having spent a while trying to get MPC's
Slave I kit cleaned up and more movie accurate, I was well aware of the asymmetry of the hull plating, so the Essential Guide's schematic looked weird to me. I brushed it off as artistic simplicity, representing the
actual ship that we
knew was asymmetrical... Until that basically became the hull plating pattern for Jango's ship in AOTC. I think that was when I first realized the people making content at Lucasfilm were fans who were driven enough to seek work there -- but the kind of fans who blindly absorbed anything they read in the EU without critical examination. Like the costume designer who created Krennic's look in Rogue One being inspired by "the Grand Admiral in the
Death Star conference room scene in the original film", when 1) Grand Admirals wouldn't exist until Heir to the Empire was published in 1991, and 2) that character wasn't even dressed like that anyway.
I could totally see Boba working all sorts of traps and tricks into his ship over the years since the Clone Wars, but everything about Jango and his ship at the time AOTC came out felt... off. Like George was deliberately giving a middle finger to Boba fans. All of the backstory, the Mandalorian Protectors and supercommandos, even the way Mandalore itself looked... I appreciate the hell out of Dave for bringing in even what he has so far from the old EU, and I can acknowledge how ham-handed he's had to be with some of it to work around George's ******** edicts. But in '02, we went from anticipatory excitement to maybe see what the ESB-era materials had described as "a race of evil warriors defeated by the Jedi in the Clone Wars" to "Jango is the last Mandalorian".
Slave I went from "just another
Firespray-class system-patrol craft commissioned by the Mandalorian government and jointly built by them and one of the GFFA's shipyards, and after the Clone Wars there are very few left" to "Jango stole the prototype of a new ship some company was building and used it to destroy the facility so no more could be built".
The clone thing I'm still not sure how I feel about. My kneejerk reaction is still that it diminishes Boba. In my Absurdly Ambitious Big Star Wars Rewrite, I have Jango, Arla, and Boba as the three Fett kids, orphaned by Death Watch during the last Mandalorian Civil War before Jango and Jaster's group were able to take them out. When another member of House Vizsla restarted Death Watch, Boba -- who had been to young to realize what had happened to their parents -- joined them. When he ended up being inadvertently responsible for Jango's death during the First Clone War, he left them and became a Protector, himself. But that also ended badly, so he decided he needed to never be around anyone.
But, to
Joek3rr's original pondering, the earliest anything I remember going into what Boba's ship had on it or in it was West End Games' Galaxy Guide 3: The Empire Strikes Back (later collected, along with GG's 1 and 5 into the Movie Trilogy Sourcebook), published in 1989. It has a face-on B&W photo of the filming miniature, so the asymmetrical hull plating was apparent to any kid photocopying it and using a Micron art pen to delineate all the panels. It vaguely mentions customized additions to the original loadout hidden behind hull panels. The stats include teo two main blaster cannons on the nose, a front-pointing concussion missile launcher, a front-pointing ion cannon, and a "turret" mounted proton torpedo launcher, without clarifying where any of those other weapons actually are.
WEG's second edition of the Star Wars RPG rolled out in '93 -- updated versions of most of their rulebooks up to that point, slicker art design, better art... From the publishing date, I imagine that's when the Essential Guides also got started, and they took their cue from what WEG had put out -- as did so many others, and for the same reason: It was the only source of material or information that wasn't in the films themselves, the Marvel comics (that had recently ended their run), or the half-dozen novels and novellas that existed prior to Heir to the Empire kicking off the Star Wars Renaissance. Dark Horse had only been going on their run for a little while, and their offerings, to that point, were Dark Empire and Tales of the Jedi (all outside the scope of the OT) and reprints of the old Archie Goodwin newspaper strips (fun, but about as canon as the Gold Key Star Trek comics -- save for his adaptation of Han Solo At Stars' End).
So, like a lot of things WEG published, they made it up to pad out game content and it got picked up as gospel by everyone that came after. Like five-mile-long super star destroyers and crystal-powered lightsabers.