I bent the tabs on the trim tab, but made a riblet for the elevator skin as I was too concerned about botching the tab and having to get a new skin. To rivet it in place I used some MK3129-BS rivets. You just drill everything as per usual using a #40, deburr, dimple, then reassemble and open the hole up to 7/64" for the MK319-BS rivet. Having some Mk319-BS rivets on hand during the build is handy. Given that they are oversized, if you ever botch setting a 3/32" solid rivet, and have to drill it out but have opened the hole to much to set another 3/32" rivet, it's handy to set an MK319-BS rivet instead.