I can confirm that an ARS gave me the MLRS ship type. The part where it gets tricky is wondering whether or not it's a SPECIFIC ARS on each map that will give it, or if it's only the first one. And yes, it did just show up in anything capable of constructing ships. (ark, mkV shield)
On another note, I was only able to build mk I MLRS and decided to check if that's where the bonus tab in the tech slot comes into play, but found it nowhere. Again, I wondered and worked my way to the next ARS to see if that one would give me capability of unlocking mk II and so on; etc. It didn't.
