A few things to note -

After bulkhead of the wanter tank area was skewed somewhat (I haven't found anything built here that *isn't* skewed, though, so that's not unusual... ).

The tank was bone dry and appears in fine shape.

In the last pic, the 3 tank keys shown were all found *under* the tank.

The outline directions in the manual are good, tank came out with no problem. But it was not glassed in at all, just setting there.

I made the long cuts with a skilsaw, and finished the corners with a jigsaw. Plenty of room between the blades and the hull per the directions. Not a very long job at all.

It looks like if a tank were made integral to the hull in this same location, it would hold a lot more water.

More grey-colored inner hull is evident. With resin drips over it from when the plywood was tabbed in, so whatever this mystery color is, it was installed by Pearson, and has held up really well.