I have reference images and sketches with dimensions for correct size of objects. I have about 150-200 high resolution pictures of the park different angles and some closeups for textures (hopefully) when I get to the texturing.
But here are the bleachers for now. Only including a couple of the reference pictures, because you don't need to see 10 pictures of 'em haha. There won't be close ups for the bleachers in the scene so I'm not adding the bolts as of yet, I might anyway just for the sake of having them.
Me measuring bleachers:

Back side of bleachers:

Model of bleachers:

Wireframe of bleachers:

Edit: Putting current progress in first post for WIP Thread Thumbnails.