Here is the final image
Feel free to post any coment
I worked mostly on the yellow channel in CMYK mode , made corrections using a new layer in color blending mode.
I tested mistermondeys method using the lightness channel from LAB mode and i find out that this was the perfect final touch after repairing the spills normalizing the light tones specially on the worked areas.
The printed image looks very good
Thank you all for the help
Simon