Hi Mike
Thanks again for your posts. You certainly do know where to look!
Oh yes, the good old ambulances designated HMNZT. Our little collecting group have had a really good laugh about that....
I know the one site to which you are referring and that's fairly typical of the depth of their knowledge. Problem is when it is "writ large" in one source it gets repeated.
A friend contacted them offering to sell them a nice badge (he had others but thought that he would start with one and gauge the reaction) but was told "we are unable to help you".
By the way, a big museum did a lovely book on WW1 ephemera and they showed a badge that I knew had to be WW2 as the makers didn't set up until 1921. Contacted them with a copy of a 1941 advert selling these badges, including a picture of the badge. Embarrassed silence and then a "we were relying on information supplied" answer.
Never let a good story get in the way of truth!