After getting a recommendation from Van's Builder Support to just continue working and deal with the minor dent with body filler prior to painting, I proceeded to finish flush riveting the top skin of the left flap. It was nice seeing that side of the flap looking nearly complete. I decided to pause work on the right flap since the next steps would be assuming that the trailing edge extrusion was already cut and prepared for riveting (but that part is still on backorder). So, I resumed work on the left flap by disassembling the clecos holding it together. I then dimpled the skins, scuffed with Scotch-Brite pads, and sprayed some primer on them. This time I did remember to mask off the trailing edge of the skins prior to priming, so I didn't need to remove the primer with acetone like I had to on the right flap skins. I then did the machine counter-sinking of the flap hinge brackets where they will later be double-flush riveted. Finally, I scuffed and primed the rest of the ribs and internal parts of the left flap, before temporarily reassembling the pieces with clecos. What's next? I realized that I had skipped over some dimpling of these left flap parts, so I'll have to check over all of those parts and then proceed with riveting them together. Hopefully I'll have a bit of time this Memorial Day weekend to make some good progress, but I do have some construction work to do out at the hangar as well.