Leeuwen Pugio hilt question...rivets

[Doc]

I know that the hilt of the pugio in question is iron wrapped in copper alloy. However, how is it held together. From the photos I used to have and that I know am just recalling, the back of the hilt appears to show that the rivets at the guard come all the way through and are bent over at the rear. However, the other rivets (middle and top ones on the face of the back plate) did not go through. So these are the options I am thinking about: 1) when the Roman smith made the pugio, he put the rivets all the way through the hilt but then ground them flush with the back hilt plate so they cannot be seen or snag. 2) they were peened on the inside of the upper hilt plate since they are only decorative and only the guard ones hold the assembly 3) All the rivets go through the upper plate, tang, and wooden sections BUT they stop before the bottom plate AND only the guard rivets go through the bottom plate.

I have seen in other photos of pugio hilts that rivet heads are countersunk on back plate to hold it in place but do not go through to the top. While the rivets on the top plate have decorative heads and go through the top plate securing it but do not go all the way through. This is not evident on the Leeuwen.

Any ideas?