At the end of World War I, the United States made sure they had access to the German military records in their treaty and sent a research team over there to review and copy the pertinent records. At the end of World War II, we just took everything. The allies gathered together all the material, in part because of concerns over war crimes, and eventually the entire collection was shipped back to the United States.
In the 1960s, the United States decided to repatriate the records back to Germany. Before they shipped them out they decided to copy the entire collection of German World War II records and place them on microfilm. This was a massive effort done by government contractors that took several years. Like all good government contracts, towards the end, this one was behind schedule, so they were having to cut corners by choosing not to copy things that they felt were not particularly relevant. So, the originals records are now in the archives in Freiburg, Germany (a nice little town about as far away from the old East German border as you can get). There are copies on microfilm of most of the German records, sometimes in disorder, in the U.S. Archives II in College Park, Maryland (near Washington DC). The British also have microfilm copies of portions of the German records collection that they captured over at the Public Records Office in Kew (London). The UK collection is a fraction the size of the U.S. microfilm collection, and as far as I know has nothing additional in it.
But, there were some records that were not copied by the U.S., but it is not much. For example, for the Kursk Data Base, I did the German research from the U.S. record collection. There were 17 German divisions in the offensive in the south in July 1943. I made a detailed listing of the records I have reviewed and sent that list to Dr. Arthur Volz over in Germany. He then went to Frieburg and tried to locate additional material on strength and losses from those files. About the only additional material he located was the panzer regiment files from the 11th Panzer Division, which were either not in the U.S. archives or I overlooked when I did my research. That was it. Overall, the original copying effort was pretty exhaustive.
There was one major gap for a long time. For a couple of decades, many of the original German situation maps were in the U.S., but no longer accessible. There were supposed to be copied and sent to Germany, but there was a budget issue. Meanwhile one researcher was handling them so poorly that they canceled access so as to protect them. They have finally copied them and sent the originals back to Germany.
There are also no real Luftwaffe files. Most of the Luftwaffe files were placed on a train and when the order came down from Hitler to destroy everything….these weenies actually obeyed the order and burned all their records. There are also major gaps in the German records after July 1944. Every six months, the German army units wrapped up their records and sent them back to their central archives. Because the war ended in May 1945, many of the records for July-December 1944 never made it back to be filed. Same for the 1945 records. This is why the QJM (Quantified Judgment Model) was originally developed from Italian Campaign Data from 1943 through June 1944.
Anyhow, this is an extended discussion of captured records originally inspired by this post and started with the discussions below.