You might try using some Elmers glue. Put some in a saucer and use a toothpick to get under the edges of the loose pieces. You don't need much and if you hit it with a dry iron it dries in about two seconds...you don't need very much, just a really really thin amount.
Just noticed we both posted the same solution, Lacelady :lol: :lol:
I wanted to add that your quilt is beautiful!!! Great applique work :D :D :D