Some good news for plain snuff lovers - Wilsons of Sharrow has relaunched Brunswick, and apparently made it plain. Their previous Brunswick had "just a hint of various essential oils of Mediterranean citrus fruits" and was probably akin to Best Dark and Princes. Current Brunswick Black Rappee is described as "a special coarse snuff that is dark in colour, moist and made from fine dark fired tobacco leaves", with no mention of any flavouring whatsoever. And it is strong, rated "5" in WoS nicotine scale.
Judging from the description, Kendal Brown has been changed as well - not sure about flavour, but the base flour is described entirely different now. Previous version was floral SP, only a tad coarser than their typical SP grind, medium brown, scented with geranium and citrus (some reviewers mention rose and bergamot, too). The new KB is described as "a coarse moist blend of dark fired and burley tobacco with the added aroma of lemon and bergamot" (sounds like Africa and Best Dark base).