I'm Objectivetruth (I lost my old account with the website change)
Any way.. This project can still be developed further, but here is what we developed back then.
You have two options :
1. Search for all occurences of a particular word here - http://wttruth.com/quote.html
Try searching a term like "apostate" and you will get a list of older WT articles that contain the word. Once you click on a link, you will see a Text version of the article.
To zoom into the search term while on the article hit CTRL+F on your keyboard and type the search word again. This will highlight the exact location of your search term.
2. See a Timeline of Key word usage here : http://wttruth.com/search.html
Type in a term like "Governing Body" and you will see the word usage has slowly increased year over year it capped in 1985 - 1990