Freezing the animal will make it impossible to do a Necropsy. freezing them destroys the tissue and makes pathology near impossible to determine.
I understand your concern and can't say I wouldn't have done the same thing..but if this animal has been in your collection longer than a few weeks you might want to start looking at your other pythons.
As for whats ok to save...I'd say nothing..
there is no known way IBD is transmitted or how long it can live outside a host.. trash it all.. and anything he touch or was with in 20' of..just to be safe..
Hopefully you properly QT'ed this animal..