Don't know about your location, but here in the great Southwest, we cover most windows with shade screens during the summer.
ACE and both big box stores carry "turn buttons" for the purpose of fastening the shade screens. Except for being white or dark bronze in color, these turn buttons are dead on replacements for OEM "locking tab". Bought a sack of twenty for <$10.
Lifetime supply. Look fine, have lasted long time
Fair Winds and Following Seas.