The page from Mordred's journal is under his bed, on the second floor of the Mordred Museum. You can only get it after you've found the Princess's reference to it (in the unreachable tower bedroom).
mordred's missing journal is in his study. his missing page is under his bed.
The missing page is under his bed at the museum, and gives the coordinates for the Pewter Moon. The rest is just the island storyline.
Mordred's journal is in the castle library, but it is missing a page, the one that gives the coordinates (X-56 Y-52) to the nearby moon.
Take the missing page of modred's journal.
Go to the nearby moon instead, at X-56 Y-52. (The coordinates are on the missing journal page.)
Go to the Mordred Museum. Under the bed on the second floor is the missing journal page, with the coordinates to the Pewter Moon.
You do not get or use a bucket on Astro Knights Island.
The books are informative but not essential. One is "The Mystical Weapons of Arturus" (which you get to do battle) and the other is Mordred's Journal, which is missing an important page. (see related question)
The missing journal page from Mordred's Journal tells you what space coordinates to travel to, but you still need a spaceship. Fix the saucer in the mud swamp past the mill. (see the related question)
There is no treasure chest on Astro Knights Island.
Just one : her note about how Mordred kept stuff under his bed. Once you have this note, you can look under the bed for his Missing Journal Page.
Shark Tooth Island - Professor Hammerhead's Journal is in the Shark Museum. But the important missing page is on the roof of the ruins.Time Tangled Island - Leonardo Da Vinci's notebook is on a ledge at the Statue of Liberty (1882 AD, 10 o'clock on the time device)Astro Knights Island - the journal is in Mordred's underground lab, and the missing page is under Mordred's bed in the Museum(see related questions)