True story - I had a pair of shorts that started out Navy blue and after a year or so had faded to more grey than blue. Not wanting to start any theories though...
While it does have a couple of perfect angles, the hatted Han to me still has a bit of that slightly chubby Inuit look to me seen in the early pics whereas the unhatted doesn't. The face also seems slightly too wide/big for the hat. I may try the mod you did with unhatted Luke head to mess with the facial proportions a bit. I'm sure it's the hat glue and backer piece that is distorting the face. I want to get the eye gaps and face itself a bit thinner.
I know what you mean by the HT vs SSC Luke heads. The SSC head IS Luke likeness-wise over the "sorta Luke" of the HT (the reason SSC head became my non-BD Luke on display) but the paint and detail is pretty basic. The HT has lots of shades of pinks and tans whereas the SSC is that too-dark complexion that is uniform across the face. Likeness has to trump paint apps though.