Doug,
Contact the Kingman SCF (Sectional Center Facility) which is probably the Kingman Post Office AND the Phoenix GMF (General Mail Facility)4848 E van Buren in Phoenix. Ask to talk to someone in the "Nixie" section (they usually only work days) at both facilities and explain the problem. Items found "loose" in the mail - that have no way of determining from where they came or where they were going - are routed to the "Nixie" clerk and held for so-many-days (but it is like months... 2-3-6?)

You should ALSO do this from the sending end... mail is processed in certain facilities and sent to the next facilty - usually without detours. If your package didn't have a stamp reading something like "damaged by USPS" or "arrived without contents" AND WAS CLEARLY damaged... the likelihood of the problem probably occured "closer" to Kingman is higher. I can't imagine 3 Post Offices forwarding a clearly questionable package without marking it. ONE of them would have done it.

I have never actually known ANYONE who has ever been able to find "their stuff" BUT as a former Postal Employee, I personally delivered many items many times to the Nixie section so I know they have a place for it. If there is no "stamp" from the USPS acknowledging the problem, I'd wonder about your local USPS. No carrier in their right mind would accept an empty package and deliver it knowing it was empty without officially having it "noted" - too much liability. Ask your carrier about it, plus ask him to direct you to the Nixie clerk or "found loose in the mail" area.

Good luck.