[J Witt]

Took all the nut covers off, and found corrosion under several of them. I initially didn't realize they were just covers.

So is it correct to have the covers, or is that just a dress-up item added by owners?

There are considerably cheaper prices than $250 for actual acorn nuts if you buy from a hardware vendor. If someone wanted to get together a number of buyers, they can be had in quantity at a relatively cheap price.