Well, 'civilian' in this game means pretty much a lot, the Hawk is sold in Kusari (on Blood Dragons' Kyoto Base too), the Falcon is sold mainly in Rheinland and the Eagle in the Border Worlds (by the Zoners). Also, the 'civilian' ships are used by many factions including the majority of pirates. So, I think that if we say 'civilian', it means 'non house military' - everyone can use those. As for who makes them... it's dark in there.
On the other hand, here's the answer to McNeo's question not long ago (ingame) 'why is Nightfall screaming about balance so much?' - Because it's much better to see various ships being used.
If the stars should appear one night in a thousand years, how would men believe and adore and preserve for many generations the remembrance of the city of God? - from 'Nightfall' by I. Asimov The Outcasts consider Siniestre Nube a sacred place for several reasons. Early explorers discovered a jumphole within the depths of the cloud that leads to a strange world of ringed stars and strange craft. All ships in the burrial ground are placed facing that hole to honor the Alien Spirits. - An Outcast rumor