Margate = Balkan Sobranie Original Smoking Mixture
Exotique = Sobranie 759
Having smoked all of them I'm confident they're different blends. But the Germain's products may have been created as matches, though not very successful matches. Or, all that "equivalency" stuff is just another story from the big city. From what Greg shared, these were blends that Germain's had created that were either "dormant" or for their private label business.