It took several days of soaking to get all of the white paint off of the other flares. The purple stuff doesn't seem to touch primer-surfacer layers so that took a lot of 80 grit sandpaper and a Black&Decker Mouse sounder. That stuff is hard as rock. That is the reason the flares still have a yellowish tint to the white plastic. I had to get most of that layer off to see where the stress cracks were. I also found some more serious cracks from impact damage on one of the flares.
Here is a close up of one of the stress cracks in the lower front spoiler:
I ended up fixing these by using the plastic welder and smearing at across the cracks perpendicular to the direction of the crack. This melted the plastic back together. It took a while to get all the cracks welded up.
The marks in the lower portion of the flare are from the stress crack remelting process.
The black spots are where I used black ABS plastic rod to weld the majpr impact damage cracks back to gether. Once it cools it is sanded down with 80 grit.