Vans' says in the manual that the flap is the easiest control to construct - it is most certainly not the easiest to rivet - particularly solo!
To make the bottom/top skin row of rivets easier to buck I first filed down/polished the surface marked in Image 1 and marked the centre line in red.
I then added a scrap peice of angle as a shim and added several layers of duct tape so that the red line could be seen through the rivet hole. Knowing that the rivet would be in the centre of the bucking bar I rivetted away and was pleased with the results, though my knuckles took a bit of a bashing!
