Yay! Finally got the photos to load.

Neat find! DId you decide what you will put in it? The top part has no glass, correct, so I assume there is still some air circulation. I think these things are normally sold for candles but should work great plants. Perhaps it is better to keep the plant potted, in a saucer, in the middle.

Very cute!

With regards to the bottom: I'd suggest using aquarium grade silicone to seal the edges of the Lucite-glass border as well as part way up the glass-glass borders going up the sides at least a few inches -- especially if you fill it with some soil. You don't want the metal rusting away.

Depending on the plants, soil can be used or even straight/pure sphagnum moss. (The latter is usually easy to get at Lowes or other BBS. Don't get the Mosser's brand though, that stuff is garbage. Try to get the Better Gro brand.). If using soil, do not get the stuff with moisture crystals. I'd also recommend avoid soil mixes that contain fertilizer.

Your plant choices will largely be dependent on the lighting you can provide.

dont use hot glue, but instead use aquarium glue (silicon glue). Great find and sweet.