Here is WUD’s own account of how it came about that he started work in Intellectual Property, after he emerged from the Royal Flying Corps at the end of The Great War 1914-1918:
That “junior barrister” was Bill’s cousin Agnes (Agnes McCall)’s husband, Lucius Weddrington Byrne, whose sister was married to that “solicitor”, who just happened to be George Beloe Ellis (**), the co-founder of Mewburn-Ellis, Chartered Patent Agents. (The above is a screen-grab from the InDesign-format version of the Reminiscences book. Hence the coloured page divisions). It’s clear from the date above (1978) that Bill Dykes got his book done just one year before he died in 1979.
Re (**) above, and George Beloe Ellis (“GBE”), here is what Mewburn Ellis’s own website says (at 14.11.14) about GBE himself: "John Clayton Mewburn began work in London in the 1860s, joining with George Beloe Ellis in the 1890s to form a firm which became Mewburn Ellis & Co. Six members of the Ellis family have been partners in the firm. George Ellis' daughter, Margaret Dixon, became the first woman to practise as a UK patent agent, and her brother, John Ellis, retired from the partnership in 1988”. So it is clear that GBE suggested to his pupil WUD to do exactly what he had done ie to join (eg by buying-in) an existing 19th century patent practice, and then to build up that practice accordingly. Hence the very close parallet between the Mewburn Ellis and U-D&L partnership origins.