I've been researching the background of US airmail stamps, including the issuance of FDC's. Here is a curious quote from a Postal Bulletin (regarding the issue of Scott C44):
Quote:
Stamp collectors desiring first-day cancellations of this stamp may send a limited number of addressed envelopes, not in excess of 10, to the Postmaster, Seattle Wash., with postal note or money order remittance to cover the cost of the stamps to be affixed. Postage stamps and personal checks will not be accepted in payment. Envelopes submitted should be of ordinary letter size and each must be properly addressed. An enclosure of medium weight should be placed in each envelope and the flap either sealed or turned in. An outside envelope must not be sent for return of first day covers. The envelope to the Postmaster, Seattle, Wash., should be endorsed "First Day Covers."
Given these "rules," how did large quantities of unaddressed FDC's ever come into existence? I could speculate (e.g. that established cachet makers had special arrangements with the POD), but wonder if anyone has more specific knowledge of the matter.