I am not sure whose handwriting appears on this cover. It could be that of Mr. Allen or Clara Helff, whose name appears on a number of FDCs. For the time being I am assuming that it is Helff’s. I hope to resolve the problem shortly. Note that this cover has the same 12 noon postmark as those found on the three Siebold FDCs.
Some of the FDCs associated with employees of the U.S. Patent Office have the Patent Office corner card.