As it appears you are using the seat mounts for your seat belt/4 point mounts, you might want to strengthen it up with some cross braces also. Safety harnesses should be mounted to roll cages or through the body, and the seat mounting bolts (to the body) are not near as strong as factory seat belt mounting bolts. Is the board for spacing also?
(Just trying to help you stay safer, these darn things can even roll over right behind your house. And it helps if you are using the 4 points then.)
I cut down the outside Zuki mounts, and mounted the rails on other side direct to Bombz seat mount, and I am using stock seat belts mounting points. I had to go back and add another mounting pad where it bolts to car, so I could move it outwards. (my new console was just a little wider.)
http://www.zukiworld.com/forum/build-diaries-how-to-diy/install-new-seats-93-tracker/ When that is your complete safety system, you don't want coming apart.