I don't have pics but I hauled two CPL boxes around in multiple pickups for years using a very simple system I built.

I welded a couple pieces of flat to the corner of the box and extended it out to a short piece of pipe that I used for a pivot point.  I then drilled a hole in the bed and dropped a long bolt through the pipe and into the hole in the bed.  At first I put a nut on the bolt but later realized that a long bolt would work just as well without using a nut and still allow easy removal when needed.

The box was positioned so that when the tailgate was closed it was held tight against the inner part of the wheel well and when the tailgate was down I could pivot/slide it easily back onto the tailgate.  I used it on both a smooth bed and also on a Rhino liner with success.   The full weight of the box was always on the pickup bed and didn't need to be supported.  I liked it that way because it was strong and also hidden below the top of the pickup bed.  I had one on both sides and could still hook the gooseneck or haul most anything I needed to.  The boxes were strong enough to pile the bed full of feed or seed bags, including on top of the boxes.  I could open the boxes without needing to open the tailgate if I only needed a quick tool for something and wasn't going to be working out of the box for a period of time.  For the record, one box was for tools and the other was the bolt/parts box that used to be available.

When it was time to trade pickups, all that I needed to do was place the boxes where they belonged and drill a new hole through the bed.  Drop in the bolt and take off.  I now use a service truck and consequently sold the boxes on a local sale some years ago.  Sure wish I had some pics to show you, but I don't.