The windows were barely known about and only a few references to them are to be found, for example, in the 1928 biography of Gaudí by Josep Francesc Ràfols. However, apart from these references, the windows do not appear catalogued among Gaudí’s works.
At the moment, the windows are still in a MNAC workshop, where they have been restored by specialist Valeria Mamczynski Guerizoli. While the windows were not in a poor condition, they had not been touched for years in their home in the chapel and required a good, careful, cleaning.
Source: Catalonia Today.