Blazer Seat Bracket Question

[Bino]

So I've been looking for some mystery seat brackets for a while now. However, I recently realized, that I have never even seen the brackets that I'm looking for. So I wouldn't know them at a swap meet if somebody threw them at the back of my head . See attached pictures.

What does the piece look like that goes in between my seat bracket in the first picture, and the mounting holes? I figured it's also possible that I have the wrong brackets on there and the seat bracket is supposed to bolt directly to the body. Either way, can somebody give me a little guidance? Maybe toss up a picture of what I should be looking for?

Thanks