This elaborate model's purpose is uncertain. The architectural part corresponds closely to what was built. The plaster panel showing the Conversion of St Paul is similar, but not identical, to the high relief sculpture carved by Francis Bird (1667-1731) and finished in December 1706 at a cost of £650 (roughly the same as the making of the Great Model). The relief panel is therefore probably Bird's first suggestion for the carving, and the whole model may have been made in his studio.