here is some additional info and image attached from the AFDCS:
In my collection, I have an identical FDC cancelled in Walla Walla, WA. My FDC also has the rubber-stamped cachet that was used only in Walla Walla. I also have had no luck in obtaining more information about the cover. I was told that my FDC probably is one-of-a-kind. I would surmise that there may have been only one FDC serviced at each of the five first day cities for the issue. On my FDC, the cachet is pasted on. The FDC was flown from Selfridge, MI to Walla Walla where the new stamp was affixed and cancelled. The auxiliary markings are the same as on your FDC.