Jim Carter sells two styles of bushing kits for 1947-55 Advance-Design Chevrolet sway bars.
1947 to early 1951
late 1951 to 1955
http://www.oldchevytrucks.com/cart/index.asp?sdes=sway%20bar%20bushingThe sway bar assembly at the links in the first post does not look like the later Advance-Design sway bar. However, I cannot see enough detail in the photos to be able to tell if Jim Carter's bushings for earlier A-D trucks might work in that sway bar.
Do you have a GMC or Chevrolet truck? The sway bars are different. I do not know if the GMC bushings are different from those used on Chevrolet truck sway bars.