Looks Awesome Kallen, Credit to you mate.
I think you missed what Cuppa said about the ply. He was not suggesting it as a stone guard but rather fit the ply on top of the straps and the tank on top of the ply being the ply will spread the load and the straps won't eat into the tanks when full of water. I agree with Cuppa. Stone guard will help protect from punctures though for sure.
Great job mate! That chassis looks great. Do you know a good Welder.....