Problem solved. Thanks everyone for your responses.

There were two issues in the end. The first was that the Ritchey Pro headset had 45 x 45 dimensions which were not compatible with the Look frameset's 36 x 45 dimensions.

The second issues was that the headset supplied to me was missing what are apparently called 'bearing thrust rings', which are thin, shaped, metallic discs, one for the top and one for the bottom of the head tube.

A trip to a good bike store in Sydney confirmed the first headset issue and immediately spotted the second. I now have a carbon FSA headset and my new bike is smooooth!

They also added a thin alloy spacer above my stem, which assists in the compression of the assembly upon the carbon steerer tube. I touched up the paint as required.

Now, all I have to do is figure out is where to fix the wicker basket to my handlebars...