I cannot create an article summary for Jack Eyton-Jones because the search results provided do not include this article. The search results contain information on other members of the Eyton-Jones family (Thomas Eyton-Jones, John Arthur Eyton-Jones, John Eyton-Jones of the Royal Navy and E. Yvonne Jones), but not the Jack Eyton-Jones of the BMJ article you cited. In order to create an accurate and factual summary as per your requirements, I would need access to the full text of the BMJ article on Jack Eyton-Jones.