After I did an AA version of a D class cruiser in Personal Designs, Hood advised me of the Admiralties plans and design details for converting the D class cruisers along the lines of the C class cruisers. There were no drawings or descriptions as to the layout of the ships other than to note that the main armament would be 8 x 4.5" (4x2), 4 x 2pd (1 quad), and two 0.5" quad heavy machine gun mountings. The torpedoes were not mentioned, but as there was top weight being added to the ships the first thing removed from the older cruisers were their sets of torpedo tubes. A further design utilising the twin 4" mountings (five), quad 2pd and quad 0.5" machine guns. Bridge structures and other superstructures would be kept the same as much as possible, altered to carry extra electronics outfits.
I have used the C class conversions (drawn by Novice) and the real life HMS Delhi to base the conversions on shown below.