I've been growing jewel orchids in a terrarium too. Your macodes petola looks great! As I understand it, thats not the easiest one ever to keep happy. Mine is quite small, and Ive been hovering over it & learning all I can. So far it seems happy and is showing some signs of growth. I think I will breathe a bit easier when it is larger.
I don't know if you are still looking for the wardian case you mentioned, but if you are, Terrain might well have it. They have a nice selection of interesting attractive terrariums. Hubby suprised me with one at the holiday and I've been working on putting it together with episcias and miniature violets. It's a work in progress!
I noticed that one of you have the top closed and one has the top open. How do you know which is best? Does it depend on the plants or enviorment or what? Both of your terrariums are beautiful but I do not know much about them. When I read this I think I remembered that I have a suitable jar but it open topped so I do not know if I can use it or not.
I'm certainly not an expert on terrariums. But I think it depends on the plants you have quite a bit. Also, how much moisture is in the terrarium. My episcias and violets like humidty, but have fairly thin leaves that rot easily. I keep them covered (with a clear plastic plate), but only as long as the glass isnt fogging. On the other hand, I have a couple micro-miniature sinningia that are kept completely enclosed in a jar with a lid. For these, I added only a few drops of water initially and haven't watered much (if at all) in months. Some of my orchids with succulent leaves are in glass containers that are never covered. I mist them almost daily.
The whole trick is to balance out the humidity -- enough to make the plants happy without rotting them. I think basically you have to experiment to figure out the right balance for the container and the plants. At the beginning, I watch carefully for wilt or rot and adjust accordingly -- adding more water or covering for wilt and opening the lid if things seem too wet or I see any signs of rot. After a while you get a feel for this.
I hope this helps!
PS: I use open topped jars like you mention all the time -- with plastic wrap or even a ziplock bag for a lid. Not glamorous, but it does work!
I have a post in the Gesneriads forum with a picture of Episcia 'Suomi' in a terrarium. I think that's why there aren't as many posts here as one might expect. I grow almost all of my gessies in terrariums (along with other plants), but I post in that forum or the begonias forum.