Hi again Emma,
Tonyrod has checked the Records and has found that Harry MIDDLETON details were as follows :-
Date of Birth 6th July, 1916.
Date of Death Registered - December 1989.
Age at Death - 73.
Registered District - Sutton, Surrey, Volumes 15; Page 54.
You have already received his Jap. P.O.W. Card so now have the complete information we have of him. Along with lots of photographs and information from Cliff and others. Maybe if you were to check trying to contact a Local Paper of that area their Archives may be able to assist you with copies of any information details relating to a possible Obituary etc or similar.
If anything else turns up we will pass it along to you.
All the best.
George.