I don't know how I missed it, but I didn't see your "Captain America: The First Avenger" regrade attempts until now.
I think that the first one is a slight improvement, but not as significant as would be preferable. The second one has badly oversaturated reds in the characters' faces.
It looks like you significantly reduced the sepia tint, but I'm not sure if you removed it completely. I found an easy way to remove it by color-matching footage from this shot in the movie:
...to this untinted, ungraded one from the special features:
Some scenes (such as those featuring snow) also feature a blue tint that I haven't figured out how to remove yet.
I took a crack at regrading the screenshots that you posted above (using a chain of effects, including the color match above, brightness and contrast alterations, and multiple LUTs applied simultaneously), and got these results:
It's still not quite "there" (like you, I think that the movie should have a Technicolor look), but I think that it could be helpful to you in figuring out how to make the movie more colorful without oversaturating the skin tones.