The format of the messages makes it clear that they were not encrypted with an Enigma machine. Enigma messages always begin with two groups of three letters each, which tell the receiving clerk how to set the wheels on his machine. Those groups are missing on all of these sheets, so some other cipher system must have been used. Like every other modern nation, the Germans have a plethora of different cipher systems, some based on books and some on machines. Bletchley Park has broken most of them.