Also can I ask. Does a store “blend” require that it is more than simply a renamed “brand” blend I.e. does Brigadoon have to have not only Lane HGL but a dash of something else to allow B&M’s to rename it?
I can only speak for the industry as I knew it in the 1980s and early 1990s. There were some blends that we carried that we mixed ourselves. 90% of the Blends we carried were straight from the bag and renamed to fit the personality of the store and its customers.
Lane limited was a was one of the biggest suppliers of bulk tobacco in those days. Their 1Q, (Captain Black Blue) was the best selling blend in most shops that carried it. The Tinderbox chain called it Wilshire, in the stores I managed it was called Holmes #1. If I remember correctly Holmes #2 was Lane BCA. Lane BLWB we sold under the name of Longbottom Leaf. They're always seems to be plenty of Sherlock Holmes and Tolkien fans in pipe shops, at least in those days.
I don't know of any regulations that have mandated the blend be changed before renaming. The common practice for most shops in those days was to name the tobacco after something they thought appeal to their clientele, be it a reference to Tolkien, Sherlock Holmes or a local mountain or river. Basically we looked for an image, personally or concept the customers would identify with.
I have made one visit to a local cigar and wine store that does have a small tobacco bar and carries a few blends. In the case of the Cornell and Dietz tobaccos I saw on their bar, they were just using C&Ds own name. I bought some of their C&D Bayou Morning.