Cowl rivets on a 29 Model A

[jstone154]

I am installing new lacing on my 29 Model A. I have done the radiator and now starting on the firewall cowl. On the radiator, I put the head of the split rivet on the outside and the crimp on the inside. Now I am getting ready to start the firewall cowl. Which way do the rivets go? Is the head of the rivet on the outside or inside of the cowl? I have seen pictures that looks like the head goes on the inside.