Thanks for asking merclover, great question!
My sense is such a club or organization could be a clearinghouse/resource for specific information on a particular series, as well as being a way for enthusiasts to network, learn, buy, sell, trade, etc. I realize CCF fulfills this function as well, but I presume in a very different way than some of the clubs I mentioned. But I'm not sure exactly. You got me more curious so I've pasted some info below on a few of these other clubs/organizations. Some even publish journals.
I recently asked about a 1917-S being the T16 or T17
Mercury dime variety, and none of the other merc enthusiasts offered any thoughts (so I assumed no one knew). See:
http://goccf.com/t/365500. That would be a perfect example, I could hypothetically send a photo to the 'Winged Liberty Head Dime Society' to ask.
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John Reich Collectors Society (JRCS)
https://www.jrcs.org/The purpose of the
John Reich Collectors Society (JRCS) is to encourage the study of numismatics, particularly United States silver and gold coins minted before the introduction of the Seated Liberty design, and to provide technical and educational information concerning such coins.
BUST HALF NUT CLUB (BHNC)
http://www.busthalfnutclub.org/The BHNC could be best described as a group of individuals whose main focus and interest, in fact specialty, is devoted to the collecting and study of the early United States half dollars, which were struck at the first and second Philadelphia Mints, using a hand operated screw press.
The BHNC currently consists of over 100 active collectors scattered across the country, whose primary goal is to assemble as complete as possible, a set of early half dollars by die marriage (and possibly even by die state/stage), as described in the most current book on the subject.
The BHNC is really not a club in the traditional sense. When first informally started in 1966 with six charter members, there were no by-laws, elections, or club officers; just correspondence by mail, telephone, occasional road trip gatherings and meetings at coin shows. It was not until the 1969
ANA convention in Philadelphia, that the first "official" BHNC club meeting took place, with nine members in attendance.
Early American Coppers (EAC)
http://eacs.org/Who We Are
Today EAC comprises over 1,200 members located throughout the United States. EAC members are deeply interested in the historical background, attribution, grading, rarity, and related aspects of the early coppers, as well as collecting and trading. Many EAC members are highly knowledgeable and prolific contributors to the numismatic literature of this country.