David O. McKay says not all members o the Quorum of the Twelve in 1966 had second anointing.
David O. McKay, Journal, October 25, 1966; rep. Devery S. Anderson, ed., The Development of LDS Temple Worship, 1846–2000: A Documentary History (Salt Lake City, UT: Signature Books, 2011), 365
President [N. Eldon] Tanner mentioned that following this discussion the question was raised about individuals in the Quorum of the Twelve who have not had their second endowments. I asked that I be given a list of names of Brethren of the Twelve who have not received these blessings.