Recut of the DX-9 Stormtrooper Transport model for X-Wing miniatures posted by Astrofossil. I can't actually mark this as a remix because the original is listed "No Derivatives" but I'm pretty sure "No Derivatives" is just one of the many things LucasFilm/LucasArts/Disney/etc would say about all these copyright violations, so...
What this simple recut achieves is being able to print the model with no supports on a standard FDM printer. It comes out very nicely, no cleanup is needed, and the three parts glue together easily. The back parts are easy to line up naturally, and a small tab has been added to align the front. Note that the design itself has the front cab dropped down a bit, that's not an alignment or other error.
Depending on your printer settings, the alignment tab between the front and body might fit very snugly. This has been intentionally toleranced pretty tightly. Don't force it! The tab is not super strong and can easily snap. If they don't slide together easily, trim the matching hole in the front with a hobby knife or sand it with a file to enlargen it just enough for the tab to fit.
For using this model in X-Wing, I recommend a small base. The canonical original size is right on the line between large and small ship at 20m (e.g., Firespray is ~21.5m long&wide on a large base, ARC-170 is 22.5m wide on a small base), but I think a large base would make the ship move too fast. The model has a peg hole for a standard small base, but you can also find several to print on Thingiverse, like this one. If you do want to put it on a large base though, I've included a compatible peg and matching slight tweak of rbross' large base to suit.
There are couple pilot cards & such around for the DX-9. Mel's Miniatures has one in their PDF but it's for a double length base, the pilot skill doesn't match between card & chit, and they just have one pilot, an Imperial. I recommend toposolitario's packet, which uses a small base and has a couple options for Rebel and Imperial pilots.