So how would you explain to someone still in the wts that the society specifically mentioned the specific dates the end was supposed to happen?
Re-read many of the posts in this thread. They explain how overseers were saying it. They explain how the Kingdom Ministry said it was a fine thing to sell your home and pioneer until the end. They explain how we were urged forced to reach the conclusion that the end must be in 1975. You want something to present JW's so that there is no argument with your documentation. That ain't gunna happen.
Join the Flat-Earth Society, they have indisputable evidence that the earth is flat, or join the WTS, they have indisputable evidence that their organization always is correct. In other words, you will always get an argument, no matter what you can show them.