What would you do to offer service to the current ridership at the same quality headway??
Not use the legacy fleet. IIRC they had issues with the pneumatic systems a couple years ago in the cold whereas buses and flexities did not.
The number of legacy cars is dwindling and their reliability is questionable. Keeping them around will not help keep the status quo.. it will cause more problems when cars are yanked from service for mechanical or other issues.