 Powell left Cockerell & Son in 1947 and again set up his own bindery in Froxfield, Hampshire.Here he did some of his most notable work, including the rebinding of the Book of Kells and Book of Durrow in 1953, the Lichfield Gospels in 1962, and work on many other important historical manuscripts.He studied, but did not alter, the oldest European leather binding to survive, that of the Stonyhurst or St Cuthbert Gospel, and his two chapters on the binding in books edited by Battiscombe (1956) and Brown (1969) remain the most important literature on the subject.