I did play around trying to figure out the code 4566 and never could quite nail it down.I'll try your suggestion of writing the NARA and/or Army Quatermaster for info. If the Army, by some chance, relocated his remains, John might, by some weird chance, have died in England and relocated half way around the world to HI.I did read online that a few thousand Marines were in the UK for anphibeous training for D-Day and a few in the OSS to work with the French Underground.Anyway, scrolling through the list, I saw several others removed from 4566 so that many being in England, dieing, and relocated to HI would be bizarre.
I also looked at several WWII "time line" sites online and the only big event that happened August 15, 1943 was the invasion Aleutian Islands in Alaska and that was the Army and the Japanese had already vacated the place anyway. I suppose John could have been severely wounded in a battle weeks, or months, before August 15 so death date might be irrelevant to where he was wounded. It has crossed my mind that 4566 could have been a POW camp but I'm not convinced that the Japanese would be concerned with burying the dead for later recovery, maybe an unceremonious mass unmarked burial site found and removed ti HI six years later.
All of John's siblings, and widow, are now dead and I have found two grandchildren. in their 40s, still living but I'm not sure if a grandchild would qualify as next of kin. I'm something like 2nd cousin once removed, the NARA would laugh at me.
I am now conversing by email with the 2nd wife of John's only daughter's husband,,, step mother of the two grandchildren and she and her husband are very helpful but know nothing about John's time in the military, only that he died a few months before his only child was born.