Thank you showing us this rare Neville opalescent blue piece, Margaret.
I know of no other reference photos (either online or in books) of this particular design, or indeed of any other pieces with the Neville mark. Does anyone have other Neville pieces to show, please? Is there an extant Neville catalogue of any description?
As you say, the Davidson catalogue of unregistered designs 1880-1900 shows a triple holder frame and cruets set presumably derived directly from the Neville design, and there is also a triple holder frame and cups set to match. No Davidson pattern numbers shown with either set.