Would be nice, if it were such an easy thing. I have one ship and crew, everything is part of a storyline i play. It would look odd to change something without any reason. I do not fly a ship cause of its look, i fly a ship. And i have no money to buy a new one inRP. So what?
And then some angel came and gave me a fantastic new one instead of an old, often repaired and second hand bought? Never! Then a story ends, no drama but for me it would be a little bit sad. That is all.
Swallow, it is not only legit, it is good to see new models arising, especially, if it is a nice one like yours.
But away from that: If you have a story you play since more than two years, if you put a lot of efford on it, if you always tried to do everything related to the story inRP?
Sure, i can change everything only by typing. But it wouldn´t be serious, it wouldn´t be RP anymore. Then it is easier to let a story end, everything else would be a solid lie to all the people i´ve interacted with.
So, this is not an affront against Your really wonderful new ship, it is only sad for me to see a story dying, i´ve played over the time with a lot of fun.
Maybe there is a solution, that matches with my conception. If not, then not. Then i simply have to start again with something different. New char, new faction, new game.
Why not just call the ship too old and too worn out to fly? Have the scrap value and profits over time be just enough or so to get the replacement vessel. After all ships don't last forever.
Perhaps you've been gradually remodelling it, since you can't afford to replace it? I'm sure there's a couple hundred Junkers out there that could tell you how to do it.