From my experience, building interiors can be harder than building ships. Once I attempted to recreate the A-Wing cockpit and never finished it.
But at least the Y-Wing cockpit can serve as a testbed. :-)
Creating the interior has certainly several problems that you don't find while creating the exterior.
First, the interior needs to match the exterior in geometry, because the interior will be placed in the exterior model, and they need to match.
Then, not just any interior layout would do. It needs to mimic what you could see in the original X-Wing game, that used 2D cockpits. Now, the 2D cockpits were designed to improve usability in a 320x200 resolution monitor from the '90s.
So for example the targetting computer screen needed to be of a minimum size to allow enough readable text inside.
You can see that the developers had problems with the rebel fighters' 2D cockpits when they reused them for XvT. In X-Wing, the computer screen showed little text, and a big static ship icon with some bogus unreadable text lines, but in TIE Fighter they improved the computer screen by showing a 3D model of the targetted ship, along with detailed information.
In order to allow for this, the imperial computer screens were much bigger, taking most of the dashboard space.
However, when they tried to reuse the rebel cockpits in XvT, those screens were too little to be able to show a 3D model and several stats and make it all readable. So they needed to chop away some instruments and enlarge the screen art as much as they could.
I have opted to return to the original proportions because nowadays' screen resolution allow us to display basically whatever we need on the smaller rebel computer screen while keeping it readable.
Still, you need to "translate" the positions of the instruments in the original 2D cockpits into shapes, angles and positions in 3D space for the 3D cockpit.
I needed a lot of trial and error, because at the beginning I tried to make the 3D cockpit resemble the real layout the ship had in the movies. Check here
I think the original 2D cockpits kind of attempted to keep the looks of the original movie props. For example, the Y-Wing in-game cockpit shows the shields display inside a white circle that reminds that funnel thing on the movie set dashboard. I tried to keep that in my 3D design, even when you can barely distingish the 3D funnel shape in the original 2D cockpit.
But you cannot just copy the 3D shape of the movie sets, because the actor sat really far from those instruments. If we want to keep the viewports' pillars as a reference of what the pilot sees, those instruments would look tiny in our screen, and even todays higher resolution would not help much.
So I needed to "bring" those instruments closer to the pilot eyes, so that the instruments good look ingame.
Also, the Y-Wing has an isolated set of instruments apart from the others: the two directional scopes and the laser/warhead munition counter. These are placed over the pilot's head, at the particular junction between the frontal viewport pillars and the middle section.
If the camera needs to see both sets of instruments, you cannot cheat by moving the pilot's seating position forward towards the dashboard...
I think I am happy enough with what I got done for my skill level.
In restrospect, I think the front viewport pillars should have been maybe thicker. And of course more detail and proper texturing needs to be done. But it serves its purpose for now as a placeholder.
My focus is now on making the player's ship "playable", so that this stops being a simulation to look at, and instead you can actually start flying around and killing stuff.
Most AI behaviors and triggers are still missing. But that is just matter of iterating over a working playable program.
Of all the mods and projects I've played for various games in the past, nothing has made me regret not learning coding/modeling more than seeing your work here.
Have you found anyone to help you out at all to lessen your work load? I really wish I could contribute in some way, but I don't have any of the necessary skills unfortunately. I can contribute $$$, but unfortunately that doesn't exactly speed progress on this along at any rate :)