John Barret seems to have been active from 1883 to 1900, which is a career of 17 years, yet I have only two rather odd photographs in my collection that has his stamp on it.
Lists of Barretts found in various resources-
Barrett
Centre of London Road, Lowestoft
Barrett, F.
London Road, Lowestoft (Kelly's Suffolk Directory 1865)
Barrett, John
London Road, Lowestoft (White's Suffolk Directory 1885, Kelly's Suffolk Directory 1883/1888/1892/1896)
103 London Road North, Lowestoft (Kelly's Suffolk Directory 1892/1896)
2 Church Road, Lowestoft (Kelly's Suffolk Directory 1896/1900)
Barrett, M.
37 London Road (shared with F. S. Worthington, Surgeon), Lowestoft (Mathieson's Yarmouth and Lowestoft Directory - 1867- 1868, Huke's Directory- 1892)
Barrett, Michael Frederick
London Road (Harrod's Norfolk Directory 1863/1868/ 1872/1873/ 1877, Morris' Suffolk Directory 1868, Kelly's Suffolk Directory 1869/1875/1879)