Jan 1 1989 Watchtower pg12 and the Bound volume later in the year had a very significant change...
WT: "He was also laying a foundation for a work that would be completed in our 20th century"
BV: "He was also laying a foundation for a work that would be completed in our day"
Truth book had a reprint change as well between the 1968 and the 1981 revision in the before and after 1975 hype
Millenial dawn had a pretty good change new light between the 1902 and 1924 editions.
Oz