I may have found a source for my necropsy! After spending some time with Google, I found a vet located in Allentown, PA who specializes in fish:
Pet Fish Doctor
After sending him an email and explaining the situation, he responded to me that if I brought/sent him the fish (still alive, since apparently they have to be very
freshly dead to get usable results), he'd euthanize them and perform a necropsy checking for internal parasites and mycobacterium on up to three fish for $100. If the microscope analysis led him to suspect mycobacterium (by the presence of granulomas on internal organs), it would be an additional $80 to send samples off to a lab and have culture tests performed.
as a vet, do those prices sound reasonable to you?
Obviously, even if it is a fair price, $100-$180 is pretty steep. I have well over that in plants and livestock in the tank in question, not to mention my other tanks and my own health, so I'm leaning towards having the tests performed.
Best case: it's not TB and the knowledge gained from the necropsy allows me to effectively treat my tanks and end this problem.
Worse case: it is TB, I'll have some very difficult choices to make, and if I nuke the tank I'll have $180 less to put into rebuilding it. However, I'd have a little more confidence in the decision from knowing what I'm dealing with. I'd probably still consider keeping the tank, since others have reported success with UV sterilization (which I have) and I'd likely attempt to preemptively attack the TB by dosing the still healthy-looking fish with kanamycin.
What do you guys think? If it was your tank, would that knowledge (good or bad) be worth $100-180 to you?