Yes, it may be possible to improve it, but not with an automatic fix. Damage like mold plus a badly degraded color channel usually requires careful manual retouching.

A realistic approach in Photoshop CS6 is to work on the full-color image rather than trying to restore the red channel by itself, since the overall image may be more salvageable. Tools typically used for this kind of repair are the Clone Stamp, Healing Brush, and Spot Healing Brush, combined with patient, detailed brushwork and close attention to texture and facial features.

The main limitation is skill and time: this is meticulous restoration work, especially where important detail is missing in faces. If you’re already comfortable with Photoshop’s retouching tools, you can likely improve it substantially. If not, a professional photo retoucher or photo lab that offers restoration may be the better option.