I purchased this one at Brimfield from a dealer from Pennsylvania who always has marvelous things, and who, like me, found it quite complete in itself as a fantastic sculptural object, whether to be put to function as a frame or not. Late 19th c. or so I believe, with 7 stacked, chip carved layers on the long sides, rising like mountains! And old black stain that has mellowed over the years to perfection, with a nice crusty patina on it.  I think I would  hang it on the wall just as it is with nothing inside, but it is framed out on three sides on the reverse to accommodate a picture and glass, or mirror--one might just need to add a bit of tape to the fourth side for security). With an old wire wrapped around a few nails for hanging.

8 1/8" x 8 1/2" x 1 3/4" d.  Sight: 4 1/2" x 3 1/2". Good antique condition, stable and sound, with a couple of spots of tiny surface/stain loss on the lower horizontal piece, as documented.