Well the base is the main thing I did on these so that's great :)
We touched these up, repaired them, and redid the bases... they looked quite nice as an army and I agree about the dirty thing :)
These are good "out of the ground" skeletons. I personally don't like the dirty style as much as the crisp clean bone color, mainly for roleplaying reasons -- storywise, my undead are prepared/cleaned before animation. I think the metal parts are a bit bland; not quite rusty, not quite glinting steel. The part I like most is actually the base -- it looks 100% natural in scale, like a wet forest floor. I'm a sucker for good simple bases, and this fits the bill perfectly.