The Father Christmas Suit - S2-E11
Continuity mistake: In the scene on the way to the church when Liz and Hyacinth nearly crash into the Thorgunburys' car, there are two cars parked in the front garden of the house behind them, a red Peugeot and a white Citroen. At the end of this scene a white Vauxhall Nova has just appeared in the garden.
Answer: I have asked myself the same question for a long time. It is Rosina-Queen's fine bone china, pattern "Olde England." It's the china that appears most of the time in the series. The Royal Worchester double-glazed Avignon (for candle light suppers) is really Royal Doulton Avignon, pattern "The Moselle Collection." And the Royal Doulton with the hand painted periwinkles is in reality of course Royal Doulton Colclough, pattern "Braganza."