Ok, after seeing the newest pictures, here are my thoughts...
first of, i can't remember your vet situation. i know that a lot of clinics won't even see exotics, let alone treat them. can you fill me in? thanks
now, orion has had spots that look like this on her tail before. a lont time ago she had one thta was a little bruise from getting her tail caught. now she has one on her tail that's not so great. when i brought her home from the vets after her surgery there were two white spots on her tail: one along the top and one on the tip. i used antibiotic ointment on them and the top one went away. the tip one didn't, and it turned black. it is getting a bit worse and now is really dry and bleeds a bit. i got some chloramonenicol 1% from my vets office. it's a water based antibiotic ointment and i have to say it works like a miracle!! I would suggest calling your vets office and seeing if you can get some. they won't give it to you without seeing him, but if they don't take exotics then you can explain the situation to them and see what they can do. it isn't a very strong medication and they may be able to help you out... let me know what you think!
~Lindsay



good luck!!