Found out the decoration is dolphins or Gurnards and alternating sea shells. The lamp base is a registered design, unusually as it’s a lamp it’s class 1 for metal not class 3 dates 29th May 1872 but I’ve not managed to find it in the national archives. Contenders are All from Manchester, Derbyshire brothers, Burtles & Tate or possibly Ker and Webb, any help identifying the registration would be gratefully received thanks Mike