I noticed two acorn nuts at the top of the clothes closet were loose and I could move them up and down. So I inspected them on the roof and could pull them up about an eighth of an inch. I know water could get in if I were to be in the rain. So I removed the rivets and replaced them with #10-24 x 1" Stainless steel machine screws. The rivets from the factory use acorn nuts as bucking. Photo #1 shows the location of the two rivets and photo #2 is a close up to show that rivets used were too long to snug up. The other photos show the sequence to drill out the old and replace with the machine screws.
Done! Took me as long to write this and upload pictures as it did to do the job.