Personally I would almost go the other way around (UN then blood). The WTS has admitted that they were an NGO, but they haven't admitted that their blood policy is wrong (outright - however it has changed over the years).
I'd start out with the letter from the UN saying that they were an NGO and the time period and get their reaction (which will be, "There's no way!") then I'd get them to keep that reaction in mind and go through the criterea for being an NGO, such as agreeing to the charter and policies of the UN and to promote knowledge of the UN by printed material. Then after doing that, I'd bring out the letter from the WTS (I have a copy I can scan and email you) that says "Yes, we were an NGO but it was for a library card." They'll say, "there you go, there was a good reason for it." That's when you ask them if they think that God would think that agreeing to the policies and charter of the UN is acceptable in order to gain access to a library, which on a side note you could get every book from it without stepping foot into the UN building.
Kwin
