So it was never an historical result --
Nope.
I wondered if ancient history books back in the 19th century had a chapter where Jerusalem was said to have fallen in 606; turns out, the particular interpretive choice is prior to everything else.
In addition to Phizzy's Farrar 1889 reference, we have Albert Barnes' Notes on Daniel, Vol. I (1851) which has Jehoiakim's 3rd year, when Neb. took Daniel, as either 607 BC or 606 BC. He refers to Johann Jahn's chronology (History of the Hebrew Commonwealth, translated from the German in 1828, p. 134-135) who favors 607 BC as Jehoiakim's 3rd year and dates Jerusalem's destruction to 588 BC. Barnes also refers to Bishop Usher's chronology (1650s!), the standard of the day. Usher dates Jehoiakim's 3rd year to 606 BC and Jerusalem's destruction to 588 BC.
When the correspondent (quoted at the top of this page) brings Usher's chronology to Russell's attention, Russell counters by saying,
1. We see no reason to change - it'll mess everything up;
2. We've dealt with the objections already in Studies II;
3. Ancient histories are unreliable, however, Cyrus' 1st year is well-established and generally agreed to be 536 BC;
4. Usher made a mistake in associating the 70 years with captivity when the Lord/Bible expressly associated the 70 years with the period of desolation, 'without inhabitant' which only happened after Zedekiah was dethroned;
5. Did I mention that if we changed anything, it would mess everything up - and I mean everything - the Jubilees, the parallels, the whole bally lot?