C. Seibel Sherbet Cups

I have 2 C.Seibel sherbet cups. Both have “100” stamped on the bottom.

One cup has C.SEIBELm.Co FFM stamped on the bottom.

One cup has SEIBEL Co and FRANKFURT stamped on the bottom.

I can’t find anything on the web about the company or these pieces; any help is greatly appreciated!
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