Codex Wallerstein was owned by Paulus Hector Mair, an avid collector of fencing manuals and an author in his own right. The text was purchased on January 26, 1556, meaning it probably post-dated Mair’s own encyclopedia on fencing.
The text itself begins with plate 5 and is titled “Length”.
It advises the fencer to take a low stance, as it is allows for good reach and expulsions. Expelling the blade by cuts against the flat are of course an important technique in any school of longsword. “Standing behind your sword and bending yourself” is also noted as being important for both attacking and defending. Finally it says that you should make yourself small so that you will be “great in your sword”.
So far it sounds a lot like rapier, much more than any other longsword text I’ve come across thus far.