obsolete hexaprenyldihydroxybenzoate methyltransferase activity (obsolete GO:0004395)
OBSOLETE. Catalysis of the reaction: S-adenosyl-L-methionine + 3-hexaprenyl-4,5-dihydroxybenzoate = S-adenosyl-L-homocysteine + 3-hexaprenyl-4-hydroxy-5-methoxybenzoate.