the bolt heads are behind the paneling on the inside so maybe a custom order from the factory?
I was going to cut them off but maybe I can use them for something.
thanks SRHoffman..you are right. The bolts lines up with the slide so it must anchor the insert that goes in the slide.
If I ever take the lid off I'll have to check them out because they look after market to me.
I put nuts on them and four little metal plates I found.