A quick corrected chronology for JWs is as follows:
1335 DAYS PROPHESY/1874: 1874 was based on the 1335 days prophecy. This is corrected to 1992. The 1290 days must be the "END of the gentile times" which is when Palestine was returned to the Jews. Add 45 years to get to the second coming from 1947 and you get 1992.
1914/END OF GENTILE TIMES: As noted above, the end of the gentile trampling of Judea was in 1947.
1914/SECOND COMING. As noted, the second coming does not occur until 1992, further if you follow the scriptures it doesn't come until late in the last "generation" of 80 years past 1914.
1914/BEGINNING OF LAST GENERATION: This is correct.
70 WEEKS PROPHECY: JWs are incorrect to apply to Nehemiah in 20th of Artaxerxes, but correct in dating it to 455BCE. Substitute the 1st of Cyrus in 455BCE for the return of the Jews from Babylon when the "word goes forth to rebuild Jerusalem." Thus 455BCE should replace 537BCE.
607BCE as FALL OF JERUSALEM: Corrected to 529BCE. Witnesses are correct in insisting that the Bible applies 70 years of desolation ending in the 1st of Cyrus, but incorrect in when it begins. Both the Bible and Josephus begin this combined period of "desolation" of the land and "servitude" of the people at the time of the LAST DEPORTATION, which is the 23rd year of Nebuchadnezzar. Thus the 23rd year of Nebuchadnezzar per the Bible should be dated 70 years prior to 455BCE which is 525BCE. That means the fall of Jeruslaem 4 years earilier must be dated to 529BCE.
7 TIMES PROPHECY/1914: As noted above, this must be corrected with the correct date for the fall of Jerusalem in 529BCE vs 607BCE. When this occurs, 1914 moves to 1992.
Hope that helps. But the EASIEST argument against 1914 is simply to note Jeremiah 52:30 and quote Josephus as indicating the 70 years begins in the year of the LAST DEPORTATION. Even if you don't agree with the 455BCE chronology for the 1st of Cyrus, the witnesses are still 4 years off in dating the 70 years correctly.
Canon