Fusion is not a good choice for models. Fusion etches plastic. It's good for plastic outdoor furniture or other objects for which a fine finish is not the goal, but it is not a good choice for models ... as you've discovered.
I have not tried to salvage a body painted with Fusion, so I don't know what you can do with this. I tried Fusion when it first came out, before anybody started hitting the internet with posts about it. I had the same result. I just scrapped the body because it looked too damaged to salvage.
My second instinct would be to try removing the paint (soak it in Purple Power) but you may have to sand the texture out of it. Perhaps some primer-sealer will fill some of the etching, but you'll likely lose some of the desired detail of the body.
Anybody have any experience trying to rehab a Fusion (or hot lacquer) application like this?