Ok... so, we know that the Legion models are somewhere in the neighborhood of 34-36mm tall. An average American male is 5'10", or about 1.78m. In 1/48 scale, that works out to the average American male being 37mm tall. That's pretty close. What this means is that 1/48 scale models should work pretty well as Legion terrain.
It also means that if you have a 3D printer, you can download any of the ships designed for X-Wing scale (about 1:270) and scale them up 562.5%, which would print them at 1:48 scale. Detail might be a little light depending on the model, but could work perfectly for a crashed model or a model with comparatively low detail to begin with. My plan is to try it out over the next couple of days. A dude named (I think) Astrofossil has some good models I plan on using as test models.