My mystery daffodils have been identified. I sent a picture of them to Van Engelens, a bulb company I often buy from. Jo-Anne sent it to a connection in the bulb industry in the Netherlands who identified them as Mrs Langtry, a variety that dates back to at least 1869 and which was named after Lily Langtry, actress and mistress to Edward VII. I love knowing what they are and something of their provenance.