Yes, I designed both that tub kit and the DInoot Jeep-tub trailer kit. Built Dinoots don't come up for sale often and that looks like a very nice one.
I'll be happy to answer any questions anyone has about them.
BTW, here's a video from the recent virtual Overland Expo about equipping a trailer for overlanding, one of the featured trailers is a Dinoot and the other is a military surplus M416 (but everything done to that trailer also applies to the DInoot military tub kit. (I had nothing to do with this video).