I think Szymon Infeld is a very good match for Sz. Ajnfeld. He lived at BRZEZIN 98 and Braune 82.
I found the following people living at BRAUNE GASSE 8 FLAT 1 and BRAUNE GASSE 8 FLAT 2.
I’m guessing that one of these women was his mother and the rest were his aunts. I think Chil and Liba were possibly his grandparents and Bajla (born 1939) and Sura (born 1923) were his cousins/sisters.
I found on Yad Vashem under List of Polish citizens who perished in Dachau, 1939-1945 a Szymon Infeld born 07/021925 in Lodz, Poland and he died in Dachua on 19/03/1945. He arrived on September 1, 1944 and his prisoner number was 97904 and his wartime address was Brzezinskastr. Also note his comment 01-September-1944 V.Auschw. I'm not sure if that means he came from Auscwitz or not. I believe this is the aforementioned Szymon Infeld due to the same birthdates. I wasn't sure where to enter the information I found so I entered it into stage three.