I don't have necropsy pics that I can share, sorry.
Bery basic on the inside. Simple GI tract and basic organs. Not much muscle to them at all. Eyes were HUGE (obviously), and were more complex than I would have expected.
My biggest issue was most looked like they had been brought up from depth too fast when caught. They are fairly deep water animals, and thrive in cold dark areas. the ones we had were bycatch, and weren't specifically collected with the idea of them staying alive long term. I've never heard of anyone having success keeping them long term. Most exhibits are short lived, or constantly restocking them.