It matches the boat. Original.I see the manufacturer tag. Does the year of fabrication match the year of boat. It will tell if the tank was changed out before or was original.
It was installed really well. The compartment was mostly dry, most of the foam wasn't wet, and it sat on rubber strips too. So no surprise it lasted this long.
I suspect it sitting on land for so long away from the saltwater plays a role as to why they're in such good shape.