I am missing a few in each of my kids' books. I keep a list on the fridge and go through my change every so often hoping to find them; the sad part is that their grandmother gave each grandchild one of each quarter; but my kids never got them into the books LOL.
BTW, we have books that look much like the one you pictured, and the quarters keep popping out; I have resorted to pounding the coins in their spaces

How did you get the coins to stay in??
Kim