Sorry to hear about your loss.  I have a 
suggestion.  At one point I thought my post 
office lost a package (my post office is a main 
center).  Anyway, I went to get an EMS delivery 
(had both notices for 2 attempts at delivery) and 
they said it wasn't there. I zoomed back to my 
house (the same day) hoping that the postman may 
have taken it again out on the run.  Luckily he 
was still in the area (I had already checked and 
noticed that it wasn't at my house) and asked him 
about the package.  He remembered it and said 
that he didn't place those packages where they 
normally go and that he put it in a place called 
the "REG ROOM".  Apparently this is where they 
put registered mail and sometimes the EMS stuff 
goes in there.  Maybe you could ask your post 
office to check their REG ROOM.  Good luck