Consider this description from Manciolino,

The second is called “guardia di testa” which is made with equal and even extension of both arms toward the enemy in this fashion: that when you will have extended your fists, they will be found between and at the height of the shoulders, differing only in this, that the sword hand must lie somewhat lower than that of the buckler. But coming to the feet, I say that they can be found in two ways, either with the right or with the left forward in large pace, and nonetheless it will be the same guard, for the aforesaid reason.

Without the buckler, Marozzo shows it thusly,

With the buckler, what does it look like? Most interpretations I’ve seen so far has assumed that the buckler is square as it would be in Guardia Alta. But what if we instead turned it sideways?

It seems as those we can fit Manciolino’s description of this guard to image of the Halpschilt (half-shield) from MS I.33.

Having the hands close together does seem to put it at odds with Marozzo’s plate, but there are arguments to consider:

Manciolino and Marozzo are not the same person, so their interpretation of Guardia di Testa may differ. (Giovanni dall’Agocchie has a very different Guardia di Testa.)

Perhaps placing the hands together is appropriate when using a buckler, but without one having the hands farther apart is preferable.

You can also split the difference. That is to say, have the buckler turned as it is in Halpschilt but keep the hands further apart with a bit more traverse angle.

Implications

Where I first started studying this form, it was generally taught that Marozzo wants the bucker and sword more high than forward, somewhat like the way the modern Giovanni Rapisardi draws it.

If it really is more like half-shield, then many of the sequences from Marozzo that we’ve been using will need to be modified. This can also have a knock-on effect for the Tramazzone.