Mine were broken so I fibreglassed some new mount points in!
It's been a while since they've been off but...... you could tie some string around the headlight frame while the cover is off, then attach the string across the underside of the cover, then lay a patch of fibreglass on top of the string? If it flips off then there's a good chance it won't go up in the air! If you make the string short enough it won't bop your fresh paint! Lol. Just my 2 penneth! ! Bit yeehaw but the best I could think of fresh off the top of my head!