Sorry! Your information is only partially correct! Indeed before 1961 Petrus did occasionally contain a little bit of Cabernet Franc. However, since that date, Petrus is ' Merlot solo in excelsior ' using 100% Merlot!
FYI, Tong has lost his status as Hong kong's most prestigious and famous wine collector....after selling most of his collection to Johnny Chow. Chow's collection inside a vault in ' Chuen Wan ' is most impressive and includes 1945 and 1947 Petrus!!