 The <unk> of Forgiveness and of the Kings were subject to extensive cleaning and restorative work . To replace the lost portions on the Altar of Forgiveness , several paintings were added ; Escape from Egypt by Pereyns , The Divine <unk> and The Martyrdom of Saint Sebastian . The organs were dismantled with the pipes and inner workings sent to the Netherlands for repair , while the cases were restored by Mexican craftsmen with work lasting until 1977 . Reconstruction of the choir area began in 1979 using the same materials as existed before the fire . In addition , any statues in the towers that received more than 50 % damage from city pollution were taken out , with replicas created to replace them . Those with less damage were repaired . 
