I also think it is a Cherry AN blind rivet. It was shown in the AC43.13-1 that I downloaded from the FAA site. Being obsolete, it might be hard to find a tool to pull this type rivet. I have a tool with the head for #3 and #4 rivets, Universal Head and flush, plus a 90 degree attachment. Do you know what you want for the rivets? I am not a builder, but I loaned my tool to a friend who used a few of my old rivets for a small project on his Breezy.