Yes you are correct they are grommets not rivets.The Q bolts go in them. Any Idea what size they would be. The picture you posted of the orange seat has the grommets I’m looking for. Thank you bike monkey.
[I found some very similar to the originals at a local shop where I live. They have the round top with the long stem, they are a bit long but I’m gonna end up cutting them once I get the size correct. Honestly they look like the originals. And I believe they are aluminum.