Only three reliefs and one fragment have been conserved from the original altarpiece. In the past, they were exhibited in the Basque Museum, Bilbao within a Neo Gothic framework that has been withdrawn from the Diocesan Museum's current exhibition.
The different interventions that may be observed all correspond to the same period. The Nativity scene is that which has undergone most transformation. Possibly on account of poor conservation, the entire centre panel was replaced by a new one. The female figure on the upper left corner was also replaced, as were the lateral edges of the base.
Reconstruction of figures and small wooden pieces grafted on to them may be observed in the scene of the Slaughter of the Innocent whilst certain elements, amongst which are the base and the leg of the page, have been replaced. Some remains indicate that the altarpiece had been polychrome decorated originally. The poor condition of the layers of paint or, quite possibly, the mere whim of changing trends led to the polychrome decoration being removed.
The piece shows signs of an old attack of xylophagous insects that has deteriorated the wood and caused several gaps.