aerobob,

If you are going to buy the whole set, take a look at the #912. Tower doesn't have pictures, but Dubro's site does. This setup allows for the bearing surface to be flush with the control surface and the 6-32 bolt to be perpendicular to the hing line on surfaces that have a taper. I bought one to try it and it works well.

It is not a matter of money, rather of principle. Why buy more than you need? And those $5 here and there do add up after a while.