I've riveted the '94-'95 front bumper cover back on before, though you're right that you didn't see me do it.You are on the right track. That is how they come from the factory. The get drilled out for repairs. And I've never seen anyone rivet them back on.
I am speaking of what I've experienced personallyI've riveted the '94-'95 front bumper cover back on before, though you're right that you didn't see me do it.