Why a 1970s Leviathan refit becomes a new-ship argument

How should the fictional HMS Leviathan be refitted in the 1970s if public donations could fund any conversion?

Retire her as a carrier and spend the money on purpose-built ships; a missile conversion is possible in theory but brings severe technology, specialization, and flight-deck penalties.

The fictional, repeatedly rebuilt HMS Leviathan has too little of her original identity and structure left to justify another carrier conversion. If enough money existed for the desired rebuild, ordering two CVA-01 carriers would produce more useful capability. Turning the old hull into a large air-defense ship raises different problems: Aegis and vertical launch systems were not yet mature together in the early 1970s, while older Talos missiles would create a specialized but limited missile farm. Adding launch cells to an active carrier also consumes flight-deck space and creates foreign-object-debris hazards. That problem is especially awkward on a V/STOL deck because aircraft can land across a wider area than on a tightly arranged catapult-and-arresting-gear layout.