It's...a problem.
The second volume of White Sand specifically was out of print for a long time. There is/was an omnibus edition published a few years ago that Diamond royally screwed up on delivering on time, but I think should be able to be ordered at least?
...and they shouldn't. It's a government service vehicle, form and function over aesthetics.
They could've bought a fleet of EVs off the shelf but they would'n't've been fit for service and more expensive per mile/year of use.