I meant to add that probably the only keeping info you might find would be in one of Petr Necas' chameleon books (check with Kammerflage Kreations...I know they have them), or possibly a species profile on www.adcham.com
Mouth sores can be from direct injury or secondary from poor overall health due to stress, diet, dehydration, other infections, parasite blooms. Some chams have a small gland in the corner of their lips called the temporal gland. These can develop abscesses and be very difficult to treat. Obviously a sore mouth will be very painful and keep a cham from eating or even drinking, so they just go downhill. I have heard that raising the vit. C content in feeders can help prevent it either by strengthening the cham's immune system or changing the pH of the saliva (?). I bet many nasal infections started in the mouth and were not detected.
As far as I know ellioti are like many less known species. Their perfect climate and setup requirements are simply not known, the few animals people did get were not in perfect condition, and by the time they got into the right hands they were already in trouble. Many cham keepers don't want to support trade in species that so little is known about (both wild population status and putting animals in the hands of inexperienced hobbyists). If someone feels that a particular species is the one they want to work with above all others that might be justification for buying them, but it might be a very tough battle to establish them.