This project is so simple that it shouldn't be worth mentioning, but I thought perhaps the way I did the tailgate might be of interest - it's dead simple, one moving part, but works well.
The box that they put on Gators is just too small for many uses, the sides of the bed are only about 8" high. This is probably to limit the amount of weight that can be put in there. But when time comes to load leaves, bark-dust, or branches, a lot more volume can be held without overloading it.
The rack is constructed of 1" square steel tube, welded together, and with aluminum diamond-plate filler panels. All materials are available at places like Lowes. The side extensions are 12" high, so it can now hold two and a half times the volume of stock.
I made the tailgate so that it hinges from the top, and is latched at the bottom with a center angle bracket that is behind the stock Gator tailgate. So when you open the stock tailgate, and lift the dump bed, the bed contents all slide out just like a dump truck.
The tailgate, when unlatched, can be lifted off or put back on with no tools.
Slots at the top allow the hinges to be disengaged straight up.
When the tailgate is latched, tabs on the frames keep it from moving up, so that it is securely fastened in place.
The box can be unbolted from the Gator with four bolts that attach through existing holes in the bed. The sides and front can be disassembled for easy storage with four more bolts.
Works good, but would have looked a lot better with a green frame. Next time!