Below are the Joyce listings for the G.H. Mumm printed cancels from 1900 on the 1 cent proprietary stamp, RB24. The lists include a cancel for each month of 1900, with January thru May having roulettes and June thru December having hyphen-hole perforation. All twelve cancels from 1900 for the 1 cent stamp are available according to Joyce:
Below are images of the 1 cent 1900s in my collection or sent in by others. 9 months from the list above are included in the images below. I am looking for images for February, April, and August.
G. H. M. & Co
FRANCE
1/1 1900
Yikes. Some of these stamps look like whoever removed them from the bottle must have consumed the bottle beforehand. The stamp above is kinda ragged. If it is true that the champagne led to damaged stamps, then the 2 cent stamps, which would have been removed from larger bottles, should look even worse!
G. H. M. & Co
FRANCE
1/3 1900
G. H. M. & Co
FRANCE
1/5 1900
G. H. M. & Co
FRANCE
1/6 1900
G. H. M. & Co
FRANCE
1/7 1900
G. H. M. & Co
FRANCE
1/8 1900
G. H. M. & Co
FRANCE
1/ 10 1900
G. H. M. & Co
FRANCE
1/11 1900
G. H. M. & Co
FRANCE
1/12 1900
During World War I the French government confiscated the Mumm property from the family. The Mumms were Germans, but had lived in France for nearly 100 years. During that entire time they never changed their citizenship and remained German. By WWI that seemed unacceptable to the French. Today Mumm is owned by Allied Domecq, one of the largest wine and spirits businesses in the world.