In this study, two marble reliefs preserved respectively in the Norton Simon Museum and the Louvre are recognized as belonging to the same Eucharistic tabernacle, formerly in the collections of the French painter Louis Charles Timbal (Paris, 1821-1880). The article starts with an analysis of Timbal's role in the collection of Italian Renaissance sculptures and how they became part of the collection of Gustave Dreyfus in 1872, and that of the Louvre in 1882. This explains why the tabernacle was dismembered and how its central body came to the United States, while the lunette remained in France. Through in-depth stylistic comparisons, the two parts are both recognized as the work of Antonio Rossellino, confirming the attribution that art historians already proposed for the Simon marble and for the first time identifying Rossellino as author of the lunette. That the reliefs composed the same tabernacle also emerges from a precise comparison of their measurements and the proportions between the constituent elements, in particular between those of the lunette and the architrave. Furthermore, the study of the works by Rossellino and his school makes it possible to determine the formal characteristics of the tabernacle's original cornice (replaced by a restored one), suggesting that it had fluted decorative motifs. The article is also an opportunity to explore connections between the works of Benedetto da Maiano and the Timbal tabernacle, offering new insights into the years of the sculptor's apprenticeship with Rossellino.