I have this tiny stamp in my collection and am looking for some information about it. It measures only 7x10.5mm. It is inscribed "Kaffee Reichelt", "20" and "Nordstern". From the style of the lettering, I would say it is from Germany in the 1920s/1930s.

A Google search returned a hit on a German supermarket chain called Reichelt that has stores around Berlin. The stamp does have the look of some sort of store savings stamp.
If you have any information about this stamp, please post it here. Any responses will be greatly appreciated.
Thanks, Robert
Edit: Restored photo disabled by Photobucket.