diorama style vintage Christmas ornament, tiny mirrored display case w/ mini blown glass penguins

Miniature diorama with handmade glass penguins inside a mirrored glass display. It's about 3" long, sized like a Christmas ornament (though it has no hanger).

This is mid 20th century, I think - it's showing some age and a little wear from handling though no serious damage. I believe these are the tiniest lampwork figures I've ever seen.