By the end of 1942, a mock-up of the D.H. 103 had been completed at de Havilland's Hatfield facility and was soon afterwards demonstrated to officials of the Ministry of Aircraft Production.
A finais de 1942 completouse unha primeira maqueta do D.H. 103 nas instalacións de de Havilland en Hatfield e pouco despois amosouse a funcionarios do Ministerio de Produción Aeronáustica.