Thanks for the input, guys...
One challenge I have with this orth pole region is quality refernce is difficult.
Judging color and contrast using shots of the original is almost useless due to the fading, staining, and other forms of degradation the model has experienced over the years.
The absolute best shots of the original, taken by Lucasfilm, is the shot/series represented by the photo recently linked from teh musci program, but very little - if any - of the polar region is visible in these shots.
So... The classic Muren shot.
Shows the north pole fairly well; perhaps more of the polar region than any other shot. But we all know this photo has expereinced many mutations. So determining just how accurate the colors and contrast is in this shot is nearly impossible.
In conclusion, I'm pretty OK with how it looks now. Enough to move on. Dave - good advice - finish the rest, then see how it looks. Editing while still working is self-defeating.
Today, with luck, will be the south pole, which may be done all by hand!