There are one, maybe two of those that have survived. One is on the P51 at the USAF Museum. I believe there is one paper tank in a collection somewhere. Jack Rousch ended up making a mold from the one in the collection to fabricate some for the warbird 51 owners, so you'll see some fiberglass replica's now and then on his "Old Crow" P51B as well as some of the warbird P51Ds