There have been various lists put together, although most of them are regional. They tend to be printed in small quantities, so if you see one for sale, grab it when you do. Right now, I do not know where to buy any, other then keep checking at your local bottle shows.
Other ways to locate where dairies were from is to check FeeBay and see if someone lists the town. Also Google search.
And don't forget to look through early directories that your local hysterical society should have.
Bob thanks very much for that. It does seem so odd that none of these labels have shown up, and I'm thinking more of the north American market, but even in the 1950's and 60's in the Vancouver region...