1942 Formula Lettersheet From KZ Mauthausen in Austria

Scarce 1942 formula lettersheet from Mauthausen concentration camp in Austria to occupied Czechslovakia (Bohemia and Moravia). The lettersheet folds into a cover with instructions to the sender. Mauthausen was a also brutal camp, with several sub camps. Light censor markings over instructions. Uses two hitler 6pf stamps. Reverse of letter with space for inmate's name, number, block and DOB partially missing. Overall condition has missing piece and folded top along stamps.