Usa, FDC, C72, C.d., Cachet Identification Request

This cover is listed in two of the publications devoted to cachet identification. In one it is listed as "unknown" and in the second it is listed as "C.D.". It is considered a first cachet. My question is whom or what does "C.D." stand for, if anything? Any information would be helpful and appreciated.
Respectfully submitted:
jrc531

I am not going to be of much help, but if may ask, to what two "publications" are you referring, and who considers it a first cachet? I would surmise that Mellone's volume for the 1960's is the source of "designer unknown." But what other catalog of cachets are you referring to? As for it being a first cachet, C72 is not listed as a first cachet for any designer in the Mellone's catalog of First Cachets (eds. Ausink and Monty). I did do a scan of the archives of "First Days" and did not turn up anything that would answer the question.

blcjr:

It is listed in Mellone's "The Photo Encyclopedia of First Cachets". I would just be guessing, but your version of this publication may be outdated. I did peruse the archives of "First Days" before making this post, however, I sincerely appreciate your efforts.
Many thanks for your time and consideration. Some inquiries can be long shots, at best.
Respectfully submitted:
jrc531

Checked with the First Cachets Team and they couldn't find any documentation to support "C.D." label as a First Cachet. If more information comes I will let you know.

fdcusa:
Many thanks...
Respectfully submitted:
jrc531