J.H.
I found one for my son in the For Small Hands catalog. They can be linked through www.montessoriservices.com. I liked it, but thought it was pricey, so I had a friend who is a woodworker build one similar. Due to the cost of wood, he built three--one for my son, one for his grandson and he has an extra he would like to sell. However, it is not collapsible or folding. Check out the website, if you're interested I can email you a picture of mine. If you're really interested, I can find out how much (little) he is willing to sell it for. J.