I doubt the Iceni was originally a GTVA design, I personally believe that the Iceni was create specifically for the ETAK project, and not for any GTVA needs.
BTW, welcome back,too. I posted the thread 'Liquidation' back a while ago, talking about what happens to dead project's assets (like NTV...). Will you begin to release what has not been released of NTV? 
Probably you're right, but the Iceni must have been constructed ridiculously fast after the start of the NTF rebellion if it wasn't under construction beforehand.
I think the most intelligent thing for Bosch to do was to convince the GTVA that he was building an unarmed supply or command frigate - which they may well believe, since he probably didn't order weapons or reactors for the design. This would allow the Iceni to be finished to Bosch's design roughly immediately after the beginning of the rebellion. Either that, or Bosch managed to keep the construction of a corvette-sized ship a secret - difficult to imagine. But who knows - maybe it takes a shorter period of time to construct warships in FS2 than compared to, say, a WWII battleship (a year or two).
Honestly, I've gone through too many hard drives to have anything left of NTV, other than the demo.

If anyone has the VPs, it'd be Black Wolf, Adwight, or maybe Galemp.. I'm actually considering starting the project back up again - it's been about 4 years, so I'm interested again

- but I think I might just offer my FRED abilities to ST:Reborn.