Shimano also made the Shimano Dura Ace AX for 2 years starting in 1981 with center pull brakes. Lance continued to use this design for the front brake on his time trial rig until last year since he claimed it to be more aero than anything currently available.
Here is a link to what they looked like:
http://www.classicrendezvous.com/Ita...mm_AX_prts.htm