Gene:

While I knew the APO number, but with out a date, all one could say with any certainity was that it was some where overseas, Pacifice area, as the 500 number was used for Australia, Philippines, Tokyo Japan and New Caledonia!

Of course saying Tokyo is like saying New York City! Tokyo covers a large amount of relestate!

Between 1951 and 1957 there were 8 sub post offices just for the Tokyo area as follows:

500-1 Dai Ichi Bldg
500-2 Finance Bldg
500-3 Post Exchange
500-4 Meiji Hotel (R&R Hotel)
500-5 Grant Heights (Housing Area)
500-6 Mobile
500-7 Prince Shimazu Bldg
500-8 Mobile

But at least this narrows it down to both a Country as well as a city!

John