Well, as mentioned in the above post, I visited the mining museum near Wakefield a couple of days ago. It was well worth the trip, an enjoyable and informative experience and I shall certainly repeat the exercise at some future time.
I asked two people about the term 'Dudley'. The first was an ex-miner who was working as a volunteer assisting on the paddy train taking visitors around the site. He told me that he and his colleagues referred to a 'Dudley-bottle' when speaking of the article in question. He also said that he could only assume that the name came about because it was made in Dudley (the town) or that it was manufactured by a company called Dudley.Further questions to a lady on the information desk were met with the same response. No-one could give me a positive answer as to the actual source of the name. There were examples of these water bottles around the museum but none bore a makers name.
So, despite a good day out, I got no closer to finding the origin of the name. I shall further await a response from Natalie Braber and the Dudley manufacturing company and continue to delve.
Let you know anything in due course.

Regards and thanks

Andy