Your link explicitly mentions that the equipment found in this specific vessel is probably not the original one: Speaking of equipment, it was obvious the subm

Your link explicitly mentions that the equipment found in this specific vessel is probably not the original one: Speaking of equipment, it was obvious the submarine was stripped of any useful electronic equipment, such as navigation or communication equipment. In its place were items taken from a dump. I imagine that all the original equipment was removed and analyzed by a South Korean Intelligence Service before the Sub became accessible to the public.