As it was produced for Crystalware, it is understood that they may have also been exported and while production records exist showing the numbers produced, I'm not sure how long this continued for. However, it does get very murky when I discovered there was a legal entanglement between the two companies over unpaid invoices. This is why I would like to know more about the history of Crystalware and/or Dr Muller. In any event, Chance stopped its own domestic pressed glass lines after 1953, but may have continued production for third-parties.
This set could be quite rare though. I cannot trace anything, not even a hint, of the range being decorated so I wonder if these could have been tarted up to sell them off?
Finding examples of any of the other pieces would be quite a coup! As with many things that crop up on GMB, my mind is starting to play tricks and I'm
100% SURE I've seen one of the vases somewhere... Or did I?

In any event, according to the production records, there were tens of thousands produced and many should have survived.
As for the transfers, I understand this type was produced by a company called J M Gulliver, so not Johnson Matthey, but could still be open-stock (available to all) - but it would be interesting if Chance did commission these transfers exclusively as I have seen one unknown dish featuring them.
I think the co-incidence of all these factors - not least the transfers/Crinkles on Spiderweb - clinch it for me.