That is awesome! I love using recyclables. My coop is being built with materials that were either already here or family members donated with the hope of fresh eggs I am quite sure! I am getting ready to start on the nesting boxes thanks for the cool frugal idea!
I use the square plastic ice cream buckets for my bantams and serama. Just cut a half circle opening on one side a few inches from bottom and place bedding in it. My serama hens snuggle down in theirs and feel so secure with their 4 or 5 eggs! And they don't tip over if they perch on the sides.