I thought I would post this in case it was of any use to anyone.

The following avisynth settings seem to work well for me:

Levels(15,1.08,250,0,250).ColorYUV(off_u=-3,off_v=-6).Tweak(sat=1.3)

I was using this shot:
http://savestarwars.com/images/senatorcorrected/technicolor6.jpg
from the Technicolor screening as my reference while trying to mentally compensate for the over exposure of the photo.

Ideally I would be using these settings:

Levels(16,1.08,235,0,255).ColorYUV(off_u=-3,off_v=-6).Tweak(sat=1.3)

As this matches up very closely IMO, however it causes problems with bright whites :(

In case anyone was wondering, I am a avisynth noob, this thread got me to have a go at trying to use it! ;)