Infant Stim Mobile

I am looking for a plastic swing arm for a craft project. It should be a standard, plastic, 4 or 5 arm mobile base - a bit like this:

http://www.amazon.com/Infant-Stim-Mobile-Wimmer-Ferguson/dp/B00000K3QH/ref=pd_sbs_ba_11

I'm not looking for all the decorations on the real, just the plastic base. Ideas? I want to buy in bulk, then the purchase of a mobile ready for use and modify it will not work for me.

Lobby Hobby