The nesting boxes is probably a misnomer. They are used to hold screws and small industrial parts. Any link for industrial plastics will have them. Just trying to be creative and cheap, or is it cheep?
My coop, used only at night, is a large Suncast cushion storage bin, 4 ' high, 6' long, 4' depth. Also can be used for multi garbage cans. Drilled open a large window in the back and covered it with chicken wire, have a hinged door in the front that acts as a ramp, and is closed at night. The whole thing faces into the enclosure where the banty's spend the day until they used to us. We will be putting up roosts and a few nesting boxes in there, probably little bins that I get from the dollar store and jury rig some way.
The Americauna's free load, the little snots. Lets hope the banty hens recover from stress and produce.