Query: When did Joan Hassall redesign the Royal Institute's medal?
Context: The RIBA Guide to its Archive and History (Angela Mace,1986) records that the first official version of this badge was used as a bookplate for the Institute's library and publications from 1835 to 1891, when it was redesigned by J.H.Metcalfe. It was again redesigned in 1931 by Eric Gill and in 1960 by Joan Hassall. The description in the 1837 by-laws was: "gules, two lions rampant guardant or, supporting a column marked with lines chevron, proper, all standing on a base of the same; a garter surrounding the whole with the inscription Institute of British Architects, anno salutis MDCCCXXXIV; above a mural crown proper, and beneath the motto Usui civium decori urbium ".