True but our ideas have moved on since 1960's Star Trek. Neutronium would go through a sudden phase change (actually explode) unless constrained by extreme pressure or gravity. Robert L Forward discussed encasing it in diamond but I'm not sure that would be strong enough to contain it. Nanoengineered materials seem much more versatile to me for constructing spacecraft hulls with the ability to make parts transparent, reconfigure them, toughen them, repair them and so on. Of course, this whole thread is really speculative fiction.
Ref: Neutronium - Wikipedia
[astro-ph/9707230] The fate of a neutron star just below the minimum mass: does it explode? (arxiv.org)
Interesting, so that means that neutrons repel each other and that it's only the enormous gravity forces in a neutron star that can keep them together, like a compressed metal spring.