In 1999 Clario Di Fabio proposed a reconstruction of the Tomb monument of Queen Margaret of Brabant – built by Giovanni Pisano for the church of San Francesco di Castelletto in Genoa and surviving today in a highly fragmentary state. It was undoubtedly an innovative suggestion when compared to what Max Seidel had hypothesised at the time of the exhibition on the sculptor in Genoa in 1987. On the basis of a perhaps too trusting interpretation of a drawing from the early years of the Seicento attributed to the sculptor and architect Taddeo Carlone – a project for the chapel of San Francesco of Giovanni Andrea I Doria in the destroyed Minorite church – he postulated the existence of a lost series of 'Cardinal Virtues', sculpted in relief on the front of the sarcophagus of the deceased, and of a group sculpture representing the moment of Margaret's passing away. Di Fabio also identified some of the surviving elements of the tomb monument in a ruined arch and some architectural fragments in the park of Villa Duchessa di Galliera at Voltri near Genoa. The aim of the present essay is to reject the hypothesis of a double series of Cardinal Virtrues in the same tomb and to propose a different interpretation of these vestiges and the few legible figures in the drawing to reconfirm Seidel's still valid reconstruction and hypothesise the reuse in the chapel of San Francesco, in addition to the already known surviving elements of Margaret's tomb, of two niches and four sculptures of the Quattrocento. Life-sized representations of 'Prudence', 'Temperance', 'Justice' (Genoa, Museo di Sant'Agostino) and the probable 'Doge Tommaso Campofregoso' (Florence, Museo Nazionale del Bargello), the statues are to be associated with particular circumstances in which the Florentine sculptor Andrea di Francesco Guardi must have collaborated with the Pietrasanta sculptor Leonardo Riccomanni and his nephew Francesco di Cristoforo to build the lost tomb of the doge intended for the Genoese church of Castelletto. A new document allows us to establish that following a long period of gestation from 1437 to 1460, on 28 March 1481 the work had been partially executed though not yet finished. The task of its completion would fall to Riccomanni's nephew and heir Francesco di Cristoforo, who, in his name and that of his brothers, would pledge to finish it within a year starting from the month of May. The paper also suggests that other sculptural works at Ellera (Albisola, Savona), Genoa, Lucca, Naples and Porto Maurizio (Imperia) can be ascribed in part to Andrea Guardi and in part to Leonardo Riccomanni, the latter having worked on his own or with the assistance of his nephew. Giovanni di Andrea da Bissone, one of the major exponents of Genoese sculpture in the 15th century, is also suggested here as the author of a cospicous number of works now at Barrettali and Bonifacio (Corsica), Finalborgo (Savona), Genoa and Milan.