scholar,
It's true we may have oral testimony, but that doesn't mean Gangas was lying when he told anyone who asked that he was on the committee. Believe me, he was asked a lot. I heard him claim it several times. In fact, if you have any friends who were at Bethel when he was -- and you've named people you knew who were -- just ask them and I'm sure they'll know about Gangas. The thing with Gangas was that, since he spoke Greek, he was constantly getting the question about how close modern Greek was to koine Greek. He always answered that it was about 80% the same. Which often led to the question about whether he was on the committee.
I gave a lot of tours, and when people asked if I could introduce them to someone on the GB, I could always count on Gangas to be very down-to-earth and friendly and he'd even join us for lunch, a few times. Because of this, I know that a lot of people outside of Bethel also know Gangas to have been on the NWT committee, too.
Also if my own knowledge counts for anything, Bert Schroeder was definitely on it, too. All the others, no matter how sure I am are, for me, as you say, second hand claims. In fact, I was very surprised to hear of alf's mention Karl Klein, and had never heard of a possible Byington connection.
Gamaliel