I realized that I never posted photos of the most recent revision of my dummy headset. Here it is:

The major difference is that I removed a bit more material from the inner diameter of the part. The result is that it's lighter and less expensive to produce, while still holding a fork steerer gently & securely.

The updated version is on Shapeways - please check it out and send any feedback my way!

PS - it's also available in black :) With more colors to come!