What about, when finished with that WW I vintage CL, why not refit it? What i mean is, strip away the old useless main guns and add AA weapons. You create an "AA" cruiser. this was in practice during both world wars so it is "historically" correct.       You could do the same for outher "support" weapons like torpedos or even create Auxillary carriers. All for a reasonable          price in exp or credits. It would be 1 good reason for keeping "Masterd" ships. Maybe "specialized" boarding parties to capyure ships for bounty in Exp or creds? maybe Repair ships, Drydocks in that era were rare and only the biggest most expensive ships had acess to them. Most were repared by such ships or "normal docks. Perhaps a new kind of base to capture even, the repair dock...