I found this advert in the 'Chelsea News & Advertiser' dated 11th January 1907:
“THE LIVING VOICE! GRAMOPHONE DEMONSTRATIONS DAILY - MELBA, PATTI, CARUSO, SCOTTI AND ANN HARRINGTON RECORDS. PHONOGRAPHS, GRAMOPHONES From £2 2s. to £50. EDISON GEMS, STANDARDS AND HORNS. City Sale & Exchange, 26 & 28 KING'S RD., SLOANE SQUARE, LONDON, S.W.”
“THE LIVING VOICE! GRAMOPHONE DEMONSTRATIONS DAILY - MELBA, PATTI, CARUSO, SCOTTI AND ANN HARRINGTON RECORDS. PHONOGRAPHS, GRAMOPHONES From £2 2s. to £50. EDISON GEMS, STANDARDS AND HORNS. City Sale & Exchange, 26 & 28 KING'S RD., SLOANE SQUARE, LONDON, S.W.”