Martin's Hats

I'm disappointed to learn that the book, Martin's Hats is out of print. When my son, who is now 14 and my daughter, who is now 12, were about 4 or 5, they insisted on reading the book at least daily. As I remember, Martin goes on adventures associated with a variety of hats he has at his disposal. Since my 4 year old goes on imaginary adventures constantly throughout the day, I know he would love the book. I was hoping to purchase a new copy for him, since Martin's Hats is one of the best children's books I've come across.