They are glued and riveted. That comes directly from a Ford employee at Dearborn Truck Plant.
That's interesting.
I would assume they are real aluminum rivets, and not pop rivets.
Real riveting, requires a bit of a learning curve, and has the potential, for a lot of extra work, if you mess up.
If they are near the edges, you may be able to use a squeezer on them, which makes it real easy.