The Jehovah's Witnesses: Proclaimers of God's Kingdom book on page 201 in discussing "Practices That Have Been Abandoned" admits:
"For some 35 years, Pastor Russell thought that the Great Pyramid of Gizeh was God's stone witness, corroborating Biblical time periods. (Isa. 19:19) But Jehovah's Witnesses have abandoned the idea that an Egyptian pyramid has anything to do with true worship (See "Watchtower" issues of November 15 and December 1, 1928)"
Oh, yes, they have abandoned the measurements of the pyramid because nothing Russell predicted for that year came about except supposedly the end of the Gentile times. So they kept the date 1914 to make a big issue about the generation born then, but even that had to be "adjusted" in more recent times as fewer and fewer people remained from that time period.