Sherby, Move the PM to this thread so that others can take a guess on what kind on bearing was used.
It looks like its just a precision, low friction (ball) bearing in the pendulum arm.
I just put "Knife edge pivots" in Google and found lots of info. Oh, and precision Balance scales typically use knife edge bearing (found that from the google search). Also be sure the check out the 'images' from the google search.
Added after you post:
Very small Ball bearings are available. You are just looking in the wrong place.
One source I can think of is almost any old CD, floppy or hard drive or small PC fans and if you look around lots of other places.