Can you tell me more about this German "heirloom"?

There is a construction firm located outside Munich called Emeran Huber. Undoubtedly this box was made by Herr Huber after the war (1947). Many Germans found it difficult to find work after the war, and took to making handicrafts as a means of earning cash. It's likely that this box was made by him and sold either in a shop or in person. Perhaps one of your family was in Germany after the war and picked it up as a souvenir and gave it to your grandmother. There's no record of this man in the furniture construction business, and the box is too young to be classified as an antique (must be at least 75 years old for that). As such it has no real monetary value at the present time. But depending on the quality of workmanship, in years to come it may have greater value. My advice is simply to hold onto it as a cherished keep-sake of your grandmother and to pass it down to one of your children.