The wax for the Agnus Dei Sacramentals was blessed by the pope on the Wednesday of Holy Week in the first and seventh year of his pontificate. I know that Pope Paul VI did this the first year of his pontificate in 1964. I don’t know if he did it in 1971 or not but it has not been done since. It is hard to believe that there would still be a supply of the wax from back then still available. It was strictly forbidden for the Agnus Dei Sacramentals to be made of any other wax. Also, the use of these sacramentals was not a universal practice since relatively few were made because of the strict rules. They were often handed out by the Vatican to visiting prelates, monarchs, and Bishops to use in their dioceses as they saw fit. I read that it was more of a custom for people in Europe to have them. I only know of one person who has an authentic Agnus Dei. She is an elderly nun living in Montreal. She was given it by the late Cardinal Leger of Montreal.
I would hazard a guess that any or most of the Agnus Dei Sacramentals floating around for sale on E-Bay or anywhere else are not the real thing although they may claim to be.
As to the poster who wrote Pope Benedict asking him to re-instate the “tradition”. If he had the slightest intention of doing so, the earliest he could bless the oils would be in 2012, the seventh year of his pontificate.