What’s the ownership status of the Rocinante during season 4 (Cibola Burn book)

Question

Season 3 of the TV show clearly indicates that the Mars government want their gunship back - and quite understandably so. That never gets resolved in season 3 because it’s basically introduced as an on-screen excuse for the presence of the interviewers and, anyway in-universe there is no time to argue about it with everything that happens.

Season 4 is mum about the subject. Months have passed since Season 3; Holden has an open meeting with the UN Secretary-General while the Rocinante somehow gets a rail gun (!) installed (there’s a “Chekhov’s gun” if I ever saw one) which implies at least Earth (possibly all three governments) accept the status quo. It also means that someone is willing to openly furnish the team with expensive top military-grade weaponry presumably at no cost. Obviously these guys are not hiding in the belt keeping their heads low.

For the purpose of this question I’m not looking for any event that might or might not happen after the Cibola Burn events.

The question: Do the books (or other media) address the subject of legal ownership/control of the Rocinante/Tachi at all? Has Mars given up their claim to the ship (again, at this point in the storyline)?

(One has to wonder what the official status of the team is, in the eyes of the three governments; but that would require a separate question)

Answer 1

It's covered in book 3, Abaddons Gate.

The rail gun is mentioned early on, as something they were easily able to afford having gone freelance and picked up lucrative contracts. It's justified as ammo is easier to obtain than torpedoes when they don't have a government sponsor.

In the months since he'd put up his shingle as a freelance courier and escort ship, the Rocinante had taken seven jobs, and all of them had been profitable.

Alex had pointed out the difficulty in buying new military-grade torpedoes for the ship, and had requested a keel-mounted rail gun for the Roci. It would give them more punch than the point defense cannons, and its only ammunition requirements were two-pound tungsten slugs.

The rail gun isn't mentioned again until book 4.

Ownership is resolved towards the end of the novel. Pastor Anna uses the offer of buying the Rocinante from Mars on behalf of Holden and his crew to persuade them to take Clarissa Mao back to Earth for trial. She then persuades her friend Tilly to make the actual purchase.

“What if I bought the Rocinante?” Anna said. “It’s not for sale,” Holden said. “Not from you. I know about your legal troubles. What if I bought the Rocinante from Mars. Gave you the rights to it, free and clear.”

“Tilly,” Anna said. “You remember that really expensive favor you owe me? I know what it is.” “I’m all ears,” Tilly said. “I need you to buy the Rocinante from Mars and give it to Captain Holden.” Tilly was silent. Clarissa could practically see the woman’s eyebrows rising. “It’s the only way to take care of Clarissa.” Tilly’s exhalation could have been a sigh or laughter. “Sure, what the hell. I’ll tell Robert to do it. He will. It’ll be less than I’d get in a divorce."

Finally catching up on season 4 of the TV series. Throwaway line in episode 1 from Amos:

Nice of Avasarala to settle our salvage claim.