PS. Did you see 'Flog It!' on 20 November ? A Claret Jug identical to ours was featured. It was bought at a car boot sale in Ulster for £3 and then sold at auction. The experts summary concurred with our own research. (It was designed by Dr Christopher Dresser, a modernist before his time, between 1880 & 1885 for Hukin & Heath). Unmarked and because there is no silver it was valued between £200-400.
Thanks to Moira Morrison for bringing this to my attention.