Nice one Tarby!
On the parazonium...
No actual parazonium survives. The swords identified as parazonium in art, are just that, only identified as such. We may be wrong in the identification, so there is a note of caution here, but as there is nothing else to talk about...
I don't like the reconstructed one above, it looks like a gladius hilt with an eagle pommel. The scabard is also a gladii-type scabard. The scarbard in all examples is square edged, parallel or gently angled staright sides and ended in an elaborate acanthus chape. In the so-called parazonium, in nearly all cases, the hilt is either an s-shape or rectangle, but in early cases it more closely resembles the late hellenistic xiphos, though with a much more elaborate hilt, and pommel, usually with acanthus motifs, though I have seen a few lion's heads. Beautiful. There is an actual ivory hilt in the agora museum though, so these things are real, though this might be a xiphos.
http://astro.temple.edu/~tlclark/lorica ... thensa.jpg
If the parazonium is more like the xiphos, than it would be leaf shaped, but it might not be, since they are almost always sheathed, that is a hard nut to crack. On the plus side, you could do a good impression without actually having to make a blade at all!!
I think that Antonius' length of about 15-18 inches is accurate. That makes it shorter than a gladius by a few inches. Most of the statuary is 20% larger than life-size, so just guestimating, it fits.
I'm really iffy on the s-shaped hilts. They are very prominent in the art, but from the Antonine period or later when it starts to get expressionistic. Also, on earlier examples, you can see the mechanics of the blade. You can identify the chape, the scabard throat, the pommel, etc. On the vatican examples of Lucius and Marcus Aurelius from my website, the hilts are .... less detailed.
I think there are s-shaped hilts, but this is not the best example to look at and unfortunately, I don't have an earlier one, though they do exist. There's one in madrid I think.
I am working on using polymer clay on a hilt, and I am thinking about a parazonium.
But... as always, this is how I goof off when I should be writing the disseretation... sigh.