Then I'll keep the freighters the way they are currently then.
New ships (or rather redesigns of the Viscount)
After messing around with the battlecruiser design Viscount in the sandbox for a while I noticed that the forward deck and the bridge/drive area did not flow very well (from darker grey and a more "mechanical" look in front to a rounder, cleaner style at the back), so I changed the stern accordingly.
The Renown class battlecruisers, the class namesake Renown and the Repulse
This class of battlecruiser was designed and completed as the First Hyperspace War drew to its bloody close, and they just missed the Vega Confrontation, the only major space battle of the war, by several weeks while they were undergoing crew trials. During the interwar period, the pair were given a much needed refit as several critical components were found to be substandard owing to rushed production during wartime.
Ten years later, with the Mintaka cluster breaking off and declaring independence from the Federation, taking with it all the large naval yards nearby, the now-aging Renown was once again pressed into service. The Renown was being upgraded when hostilities broke out, and when it emerged from the dockyards it was decided that the Repulse was too valuable a ship to spend the duration of the war refitting. As a result the two ships now carry different weapon loadouts.
Renown:
3x2 Heavy Railgun turrets
14x Missile Array
42x Flak Gun
Repulse:
3x2 Heavy Railgun turrets
20x Missile Array
10x Flak Gun
The Renown's better fire control system and its especially advanced "O1-B Pathfinder" radar allows it a slightly faster rate of fire than its un-upgraded sister ship. The Renown also sacrifices a little speed for slightly heavier armour (which isn't thick to begin with anyway).
The Renown and Repulse escorting Admiral O'Brien's flagship the Achilles. Moments later the Achilles would be struck by several torpedoes from the submarine U-457.
The hapless cruiser then proceeded to suffer a core overload and blow up, killing everyone on board (including the admiral). Not long after this incident the Repulse was sent to patrol Capella and was ambushed itself by G-5 "Betty" torpedo bombers. The ship was sunk and the officials involved in sending the ship there unescorted were sacked.
The Renown survived a busy war to be sent to the breakers.