antique German flow blue china salt box, onion pattern wall hanging canister w/ wood lid

Antique blue onion pattern Salt box, with beautiful deep cobalt flow blue color. This isn't marked that I could see, though I think it's probably German, late 1800s vintage.

The wooden lid has some age, but I'm not sure it's as old as the salt box itself. It looks like black walnut (very common here in Wisconsin farm country, little if ever used in Germany).

It was probably made as a companion piece to a canister set, though it's made to hang on the wall instead of stand on a counter or shelf. It measures 5 3/4" across, 6" tall at the center back, 3 1/2" deep.

Condition is rough (this is cracked, please see photos). There's some discoloration to the interior. Still displays very nicely, and the crack would be something I'd like to think could be repaired. This is such a pretty piece!