if you left it in the supplycrate then it should be in there. Just look in there and you should find it eventually. But if you hadn't saved before you put it in there then you're out of luck. I can get back to you after I play through 2 again, but that will be awhile i need to find a gamecube copy because my PS copy broke... in 2002. It has been a while so I cannot remeber where it is exactly. I do remember that there is a valve in the back shed near the RPD building. It should be pretty easy to find.
^^^ if you didnt save your game then go to the room in which you need to use the heart hey to get into and push the book cart thingy against the bookcase and climb on top of it and it's up there!