Excellent news that she is feeling better, it is easy to tell - whereas when they are getting poorly it sometimes happens slowly and you don't notice. The charity vet clinic I found on the internet was Chicago based. In England, being such a small country, we just assume charities are national like our PDSA (Peoples dispensary for sick animals).
I think your cage with the wooden frame is excellent but Casper would be whittling it to nothing in a few days