Hi, Peter.
Here is my way to make small rivets.

This copper sheet is drilled some small holes and pasted on a board.
I use 0.3mm, 0.35mm and 0.4mm diameter holes.

Rivets are made with sprue.
Heat one end of sprue and press melted part on the holed sheet immediately.

Rivets are molded.

Cut rivets.

When I set rivets on my models, prick them softly with a knife to glue and set.
Practice is required but I love this way.
Did it become helpful?
Mutsuhito