I think that looks pretty cool. But there is no need to do all that if you don't want to hack into the bedsides when low-profile side boxes are available
I still have those. I painted them green and ran them on my '92 for years. Thought about painting white for the '72, but have gotten by pretty well with this aluminum cross bed box. It's dry outside of cab storage, easy to take on and off. I use c-claps for the racks, which have angle laid along bed rails for strength, so they are easy on and off as well. I also have a lightweight aluminum cap I cap swap on there real quick