Restoring imitation wood paneling

So my friend bought a manufactured home, from the 1980s, with imitation wood paneling throughout. There has been some water damage & its gotten discolored so she wants to know how to restore it, if any products can remove the moldy-looking stains & make it look nice, as it would be quite expensive to have it repainted.

Rephrasing this-

So my friend bought a manufactured home, from the 1980s, with imitation wood paneling throughout. There has been some water damage & it’s gotten discolored so she wants to know how to restore it, if any products can remove the darkened/greying stains & make it look nice, as it would be quite expensive to have it repainted.

Watco might work. never used it on fake stuff, tho. ymmv