I also used pieces of a pink linen shirt, and deliberately used the placket and button bands to show where the cloth came from. I replaced the shiny plastic buttons though, after the whole thing was finished, with antique linen covered buttons. They sit more quietly amidst the chaos.
I'm glad I retrieved the piece from the bottom of the basket where it had languished for several months, and I'm very happy with how it turned out. As it happens, I will be leading a workshop on April 1 using the round robin piecing method (introduced by Sherri Lynn Wood and taught to me by Barb Mortell). It should be lots of fun.