I found this piece in the 'Edinburgh Evening News' dated Tuesday 24th July 1956:
“Self-Service Records - Music lovers and record collectors will welcome the opening on Friday, of a self-service record shop in the new premises of Maitland Radio Ltd., next to the Playhouse Cinema in Greenside Place. The new record department has seven specially designed listening booths lined with glass wool for sound deadening. Four of the booths have their own turntables. and three (the long-playing section) are remotely controlled by the attendant staff, but each booth has its own tone and volume control so that reception can be adjusted to suit the individual. Thousands of records are displayed in sections, from concertos, through light classical, to the pop hits of the day.”
… and this advert in the Thursday 19th September 1957 edition:
“MAITLAND RADIO LTD., SPECIALISTS IN TELEVISION AND RADIO. Showrooms: 21 EARL GREY STREET; 5 NICOLSON SQUARE and 22 GREENSIDE PLACE. Service Only: 4 GAYFIELD PLACE Telephone WAVerley 5628.”