Stronglight needle-bearing headset, probably an A9 model. Note: the races are steel and sit in aluminum cups.
Picture from http://www.geocities.com/dianne_1234/bikes/stronglightA9dimpled.jpg as of 2003/12/01.
Note the evenly-spaced dimples on both the upper and lower bearing races; the dimples correspond to common load points. From appearances this is probably the lower bearing, but the races can be switched between upper and lower.
