Since the seats were a rather difficult of the build, I thought I would dedicate a whole section to it. Hope this helps anyone installing these seats.
Installed passenger seat. It clears the parking brake without a problem and they are comfortable to sit in!
Using some angle iron stuff from Lowes, I fabricated brackets to check angles, height, position and clearance.
The brackets are going to be mounted through the metal frame using 5/16" bolts. Some bolts had to be pre-installed before welding due to their length.
Roy welded the brackets for me. I used 1" stock steel to make the brackets.
When I bought the seats, I also ordered the seat sliders. I'm using these for both passenger and driver seats. Here's a picture of the brackets that will position the seat on the floor brackets.
Side view of the mounted passenger seat bracket
View from the front of the passenger seat of the brackets. Note the offset inner bracket. This allows mounting of the bracket to the 4" round tube.
I modified the driver's side seat brackets from the passenger side design. I added an extra leg in the back to make it easier to bolt in.