Hi,
chil, welcome to RetouchPRO.
Not easy but "do-able", so you are not wasting your time.
Just need to spend a bit more.
I did not to work with the individual channels, although on your original that may be possible.
I worked in LAB, just trying to get the Luminosity right.
A
lot of masking to get the adjustments to fall into the right places.
The colours on the right-side are pretty much useless, so I just painted them in as I saw fit.
With a lot more work, and using the original, it should be possible to get a much better result.
Have fun!
Rô