Rear seat and bed questions

[bjf]

So I removed my rear load mat in my soft top only to realize that whoever installed my rear seat may have taking the short bus. All brackets that should have been on the outside of the truck were put on the inside. For example the top hat looking thing the seat locks into, the brace for it was on the inside instead of outside. This one is an easy fix, even though I am missing one of the braces. Anyway the one that is pissing me off is where the shoulder harnesses attach to the sides of the bed. Instead of putting the brace under the truck they just mounted these on top of the floor in the back. So here are my questions.

How do I fill in unneccessary holes in my bed?
Does anyone have a pic of the braces in the wheel well for a 94. the pdf is great but I want to see an actual photo. When I try to line up the seat belt mount under the truck it wont pay flush because of rivets and what not.

Thanks