Mscr.Dresd.C.93. Volume I of his manual in German in Dresden
Mscr.Dresd.C.94 Volume II: Paulus Hector Mair MS from 1550 held at the University of Dresden. Note how the otherwise unarmored fencers at sword and buckler are wearing metal gauntlets, apparently with mail protecting the palms (see 150v).
Many of the positions shown in the section on armored combat with spear and targe look remarkably like those in Codex Wallerstein, which Mair owned, even down to the positions of discarded shields and weapons lying on the ground, but with the armor updated to 1550 styles.
Wiktenaur discusses the sources for Dresden C.93-94
De arte athletica I - BSB Cod.icon. 393(1 Latin, mid-16th c., at the BSB
De arte athletica II BSB Cod.icon. 393(2
Thanks to Scott Cozad for finding these.
Codex Vindobonensis 10825 and 10826, ca. 1542, in Vienna, is written in both German and Latin. HROARR has it in PDF form.
Here is a partial transcription.
Here is his Wiktenaur page.