Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

Some primers REALLY adhere to the model. I'd try a longer soak in Super Clean (since it's unlikely to hurt the model). It also would not hurt to try a different paint stripping solution like Purple Power--what works on one primer may not work on another. Given that the plastic is both discolored and grainy, I suspect it's the primer rather than damage to the surface of the actual model (but what do I know).

If that doesn't remove it, you might try very fine grade sandpaper (the stuff for modeling, not the stuff for woodworking) or a buffing disc on a Dremel (one of the cotton ones for polishing, not a sanding disc). Those can be used to smooth plastic models ANYWAY, so they should work on this too.