Following from Clay's Infant Environment Part 1 here is Part 2 showing Clay and his infant mobiles. The above photograph is of Clay and his mum Tasha making the Octahedron. I think I can see some double sided tape there. I purchased all of our mobiles although Tasha and Charlene show that you can make them yourself.
I don't know of any one source of information for the mobiles. If you know of anyone who has completed Montessori infancy training they may be able to help. Most of the mobiles can be purchased through Etsy. At Home with Montessori also has a brief description of some of the mobiles and are based in Australia.
It's wonderful to see little Clay focusing on the mobiles. I was truly amazed when I presented the mobiles to Otis and I would highly recommend them. Like most things Montessori, it may require a little time and research but well worth it in the end.