John L. Byrum-POW in Stalag Luft IV

My name is Leonard Lanier.  I am an intern at a small public museum in northeastern North Carolina.  Last year, the children of a World War II POW, John L. Byrum, gave the museum two postcards that he sent to his wife from Stalag Luft IV.  We want to display the postcards in the section of our master exhibit that addresses World War II, but I need to know as much as I can about the particulars of his capture.  The family only knew he spent time in Germany as a POW, they did not know anything else about the matter.  Through his discharge records, I found he was a staff sergeant in the 456th Bomb Group (Heavy) of the Fifteenth Air Force.  He arrived in Europe in August 1944.  According to the NARA POW Database, he was first officially reported as a POW on September 1, 1944.  Any information at all is appreciated; I really would like more details about the mission that led to his capture and more about his experiences in camp.  John L. Byrum was from Edenton, North Carolina and worked as a minor-league baseball player before the war.  I attached a copy of one of the postcards and a picture of John L. Byrum with his father, Cecil.  Any help is greatly appreciated.  Thank You.
 

Leonard,
Here are a few pages from the Missing Air Crew Report that you may find interesting.
Hal

Thanks so much for the information, RSwank.  His discharge papers list Byrum as an "airplane armorer-gunner (612)."  I don't know if this is Army Air Corps bureaucratic lingo for tail gunner or not.  

The MACR accounts for all the gunner positions with clear letter codes except for John Byrum where it looks like there is a letter T.  My guess is that this T stands for Top (Turret) Gunner.
 
Paul

Thanks for the correction.  I saw T/TG and assumed it to be tail gunner.
Paul

Thanks for all the help, folks.  Here is a copy of the other postcard and John L. Byrum's discharge papers.

As Iccapland has noted above, Byrum was on the march from Stalag Luft IV.  There are other letters written by Stalag Luft IV prisoners that have that "odd" return address.
 
Here is a link to some letters from  Raymond E Bence, a Stalag Luft IV POW,  which show the same camp address as is on  Byrum's  postcards.  
http://notalice.com/capstone/assignments/letter_pow_19450110_raymond_bence.pdf
 
Bence's name shows up in the (incomplete) Rose roster of Stalag Luft IV.
http://www.stalagluft4.org/sorted%20roster%20cup.html
so there is no doubt he was there.  Stalag Luft IV shows up as  the holding camp on his POW record at archives.gov, same as Byrum.
 
I don't know why the "return address" is not Stalag Luft IV, but I don't think in these cases, that   "Kriegsgefangenenlager der Luftwaffe Nr. 3"     meant  they were in "Stalag Luft III".   I also don't know if the letter "B"  which is written on all the letters near the address means anything.  It might just be a censor's mark.
 

My father was also a POW at Stalag Luft IV.  He was marched to Stalag Luft I during the death march.  One of the other crewman from his plane was moved from Stalag Luft IV to a camp he said was renamed to Stalag Luft III.
 
From the airwarsk.sk web site:
"At Stalag Luft IV I was placed in compound #4, along with Lyndle Clark. The others were in compound #3. We received Red Cross food parcels, as well as potatoes and occasional treats from the Germans; we didn't bathe and had no clean clothes so we all smelled badly; but treatment wasn't too bad.
As the Russians closed in on Germany, most of my compound was put on a, "40 et 8," train to Nurnberg where a large number of Prisoners of War had been evacuated to a camp renamed Stalag Luft III. Our trip by train was not pleasant but almost all of us survived. The other compounds from Stalag Luft IV suffered severe hardship as they marched around for several winter and spring months after leaving the camp.
At Stalag Luft III we could see the almost-total destruction of Nurnberg by the 8th Air Force in the morning, 15th Air Force in the afternoon, and the RAF all night.
It came about that American ground forces were advancing quickly, so Stalag Luft III was evacuated and we walked the 100 miles from Nurnberg to Mannschafts Stammlager 7A at Mooseberg a few miles north of Munich. We were liberated there."