A good portion of the book involves descriptions of those models and their creation. He had devoted himself to building small working models of engines and other miniature machinery.
The main character in the novel is doing the same for his brother. It was recommended to me during the time that I was dealing with my late parents' estate as the executor and trustee of the family trust. Off topic, here, but if you're interested in model engineering, there's a novel by Nevile Shute with the title 'Trustee from the Toolroom' that I thing you might enjoy.
