I did look through Gulliver, but in terms of assisting, afraid I'm no help at all Sid - although for someone like me who doesn't collect this type of C19 glass, there is a design aspect of the handled cream, that seems to have the potential for confusion regarding maker.
According to Gulliver, the shell-ribbed handle was a design aspect that, at various dates in the second half of the C19, seems to have been Registered by several factories, in some form or another.........Hodgetts, Richardson & Pargeter - Thomas Webb and Bouldton & Mills all seem to have been involved in producing some very similar looking handles - the original drawings for which I've seen at The National Archives. I notice today when looking through catalogues for Sowerby that they also used this shell-ribbed design on some of their jugs etc., not that I'm suggesting remotely that your cream is from Sowerby. I can only assume that the experts can tell from the colour and shape of the finished piece to which factory this might be assigned.
I hope you do have some luck in finding a maker, but obviously not an easy task