I Pro sealed the two NACA vents to the tail cone side skins. Just in case anyone is curious, I didn't use any rivets. I did the same on the RV-6 and RV-8. As of today, none of the vents have come loose. My RV-6 is now 21 years old. I think the Pro seal will work just fine. I also installed the backing plate for the ADS-B antenna on the tail cone bottom skin.