Ha, thought you'd foxed me, Mudcat gremlin; well, I'd copied my post in case it failed, and here it is pasted in again:

On this "RW Richardson mining legend" page if you click on the "memorabilia" link, one of the photos includes a Dudley water flask.
Has anyone thought of asking the miners' union for a contact with an archivist who might throw some light on this question?