This set for sale is really interesting. It comprises some nice documents from Josef Bujoczek Polish citizen who was taken to Auschwtiz in 1942, after having been working for Siemens Schuckertwerke in Kattowitz (now Katowize, Poland) in 1940.

There's a letter sent by Bujoczek from Auschwitz concentration camp, where he was given number 37231 and also a kind of sports certificate.

It turns out that after signing the "German List of Loyality" in 1944, he was released from KL Auschwitz. He applied to join the Technical University in Breslau (now Wroclaw, Poland), but his application was rejected as we can see in another letter of this set.

Really nice grouping!