Very interesting. Nice job! Maybe that is what it will take. I don't give up easily and I'm down to give it a shot. Kill the bug or kill the fish. lol Yeah it may come to that.
I forgot to mention I gave the fish 3 30 minute baths in potassium permanganate solution the past 5 days as well.
So as of now my plan is:
1)Finish out the neomycin and oxy treatment
2)Give the fish 48 hours of clean water
3)Treat with the Chloramphenical for ? days
4)Give the fish time in unmedicated water
5)Depending on the Chloramphenocol results, would potentially treat the fish for ~30 days with Kanamycin or possibly Kana/Nitro combo again. Though an antibiotic that would last longer in the water would be much easier - so may not go with Kanamycin. Minocycline didn't seem to be effective with this, but is tough to tell as the ulcers heal slowly.
6) Get some Baytril/Enrofloxacin and inject the fish with that.
7) Find another hobby.