Gene,
You might not have gotten very far just a few years ago on the internet. The DODADD file was only available on microfiche when I first used it in my job in 1973. It migrated to propriatary government data systems files, CD and is now available on the net. Not sure anyone will find older APOs on this file. Currently open APOs that may show deleted addresses are there though. Between the DODAAD and the reference John cited we should be able to ID the location of most APO/FPO.
Still need to know more on this chip. We know who ordered and that it was sent to a military address. We do not know where it was used.
NCO Club?
Officer club?
Private individual?
Private Club (veterans, public service, charitable, etc)
Illegal Game / club?
USO?
Military organization for recreational use?
Would be very interesting to know.

Paul