You need cheap, soft aluminium pop-rivets. Like they sell in Do-It-Yourself Markets. And a riveting tool for those, of course.
You need to do it slow and tender. Sounds familiar? ;-))
If your rivets are too hard, the Paxolin will break.
I used a washer to spread the force over a larger area.
Look at my site for photos. http://www.paraset.nl/
Scroll ¾ down and you see the Type 1 sockets being riveted, and the washer use on the back side.
Now the great trick: if you riveted the socket, you are left with the broken off nail. Inside the rivet is the broken off head of the nail.
I used the nail and a small hammer to knock the head out of the rivet, from top to bottom, again: slow and tender!
I hope these drawings show how it is done to end up with a “hollow” rivet.
Look for rivets with a more or less rounded head:
I hope this will help you.