Last time i bought a lower headset race it was victory/triomphe for my nuovo record headset. The victor/triomphe is an exact replacement and tight fit with the right stack height. The NR race bottom outside is rounded (like on a sphere, like both tange/campy in the picture) and a victory/triomphe has a lower "skirt" where it goes vertical for about 1 mm, hitting the fork crown at a 90 degree angle.
Renaissance-Cycles sells NOS headset pieces .. that's where i got mine .. might want to email them because what's on their web site is not always what's available.
If you have a pitted crown race there's a chance of refreshing it by "lapping" the headset (running the race with some abrasives inside) and then using loose balls.
- Don Gillies
San Diego, CA