I certainly hope that's a mockup in the pictures!Maybe for a mock-up, but nothing else.
Two reasons. The hole drilled for the rivet removes a lot of the width of the wood longeron, which weakens it significantly. I could see a 20% loss there. And when the rivet expands it compresses and crushes more wood, expanding the weakened area.Added with lots of glue of course.
Why not ?
Actually AC nails are just brass plated (the nails are steel).why not brass nails as is standard?
Put the backup washer on then pull it tight and stop. Don't break the stem off, just nip it off and touch it up with a grinder (flapper disc 120 grit) to finish. The glue and rivet should fill the hole. But as always, you are "designer in chief", and responsible for what ifs. So test to destruction.
While we are on the subject of non-standard construction, I have one I've never seen. Has anyone ever metalized a wood wing? Could never find any information on if it was tried. I'm guessing it may have been and it failed? The expanding and contracting differences of wood and aluminum comes to mind. If a wing is sitting in the sun, would their dissimilar properties warp things?