Are you sure that is blister disease ?
How does the belly look? I don't see blisters per se..
Does she have mites? I know the brown pieces are substrate, but I also see black round tiny dots on her. Burns can look like blister disease. I think that snake has been over heated and/or around chemicals or disease.
If there are mites, I would maintain the strictest and most absolute quarantine. Diseases are carried by mites, and every time you handle those snakes, the mites might travel on you to your collection.
If they have mites they may have been subjected to some "home brew" mite treatment. The wobble is simply neurological damage. Where it comes from, hard to say. Not genetic I don't think, there are no morphs in there that carry the so called spider wobble.
Time and good care will tell whether that is a temporary problem. Given they came from such rough conditions and unknown where they were purchased, quarantine is of utmost importance.