Some great replies thanks.
I do feel the 1914-1919 period and the supposed "choosing"and "appointing" at that time is the vulnerable 'Achilles heel' for the Org.
It can be presented as a very valid challenge "Look, I will stay (or join) if you can prove Scripturally that God said he would have one Org, and that the Society is it and was chosen in 1919. If you can do that, as you should be able to, I'll stay."
As soon as we get to the "Slave" Scripture, they have to prove they were "Discreet" and were feeding pure food at the proper time - but their own publications show this to be totally false.
Then when we get to the "Wise Virgins" Scripture - another supposed 1919 prophesy about the Society - they have to prove they were "awake" when the cry went up that the Master had arrived. They had to be ready at the time. Unfortunately they were wrongly teaching he had arrived 40 years earlier in 1874, so they were "asleep".
And the biggest gift the Society has given us relating to this pivotal time of supposed "choosing" is that, just as some quoted on the previous page, they lie now about what they preached in the run up to 1914, which shows they know full well that what they taught them is a 'black mark' against them and would disqualify them from being "chosen". This lie is easily exposed, because it just involves comparing quotes from now and then.