Of course the little towns in Buenos Aires are not European villages, and could never be. They are Argentinean towns. And I think that they have character. An argentinean character. Of course many of them could do with paint and gentrification, but the charm of the spider webs between bricks in buildings of the 19th Century is hard to dismiss (like Uribelarrea, as an example). Should gauchos dress like cowboys or French peasants?
In Angkor (Cambodia) the restorer groups decided to maintain one of the temples as it was found in the 19th century. It is called the "Jungle Temple" or the "Tomb Raider" temple. It is one of the most visited, and the decision was one of the best they did, as gigantic trees are encroached over the ruins giving it a magical air that would not have otherwise. It was cleaned, but the idea is that you can feel as an explorer being on the middle of the ruined stones.
So maybe the solution is to paint and clean most of the historic buildings (as it is done in Azul, or Villa Maria -Cordoba) and let a couple shown as "old", of course doing the reparation works so they stay upright.
Finally, the charm of the Lujan Basilica is that is kitsch, is the Basilica of the People, where you see dogs and cats and people eating while they attend mass. It is alive, and doing well.