Glasgow Corporation L210, SGD112, a Leyland Titan PD2/24 with Alexander H33/28R body new in 1958.
Glasgow had the SGD registration reserved for its own use (and before that the FYS series), running from SGD1 on a 1958 Leyland Titan reaching SGD740 on a 1963 Atlantean before the year letter registration system came in and they lost their special system.

Photo taken by Andrew Green, July 1972, Glasgow