Turning Crown Colony cruisers into modern mission ships

How could Crown Colony cruisers and Tribal destroyers be modernized for contemporary missions?

Cruisers could take gas turbines, missiles, radar, and a hangar, but the Tribal hull is too small; cruiser displacement is roughly the practical lower bound for the full package.

In this hypothetical, surviving wartime ships become available for modern Royal Navy missions. Crown Colony-class cruisers offer enough hull volume to consider replacing their machinery with gas turbines, installing radar and vertical-launch missile cells, and turning the stern into a helicopter hangar. The existing 4-inch gun positions might accept close-in weapons of roughly similar weight. Smaller replacement machinery could leave additional space for missile cells along the centreline. Town-class cruisers receive a preference for this work, although the Crown Colonies remain plausible candidates. Tribal-class destroyers are judged too small for the proposed collection of modern systems.