How to correct CP'd sky in Photoshop?

I have several photos taken with relatively wide angle lens and with a polarizer, with the result that the sky color is grossly different in different areas. What are some good ways to fix that using Photoshop? I'd prefer not to do a complete sky replacement because of the problems of getting the selection right, but maybe I have to go that route?

Thanks
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My photos: http://photos.moxis.com