I had a spare few minutes at Kew today - so I had a quick look for James Hammond in the Japanese POW records. There are only two cards for men named James Hammond, the only one that looks possible is this one:
James Hammond born 1/05/1918
Private 297826 2nd Battalion Argyll & Sutherland Highlanders
Place of capture: KLUANG
Father's name: James Hammond 116, Ferguslie Avenue, Paisley
Mother's name: Jean
Place of origin: Barrhead, Glasgow
The only name of a camp [in English] would seem to be somewhere called Eachern
I know that the above does not tally with the information that you gave earlier - except for the Barrhead connection, but the only other card was for an obviously English James Hammond with absolutely no connection to anything Scottish. Hope that it is of some use.
jds1949