I'm a far cry from a expert, but i think a lot will depend on how they were made since you indicated that he either had someone make them or did it him self. Are they true sliders that bolt on underneath, or is it just a strip of diamond plate that is going to go along the rocker?
Which ever it happens to be, i don't think you will have much issue, should be pretty straight forward either way. Biggest problem will be rusted hard ware if they attach under the jeep.
"Time you enjoy wasting, was not wasted"- John Lennon
"The Jeep is a manly device. And a womanly device. An American device. It’s a fitting instrument to transport the free people of a free nation with the respect to which we are entitled and the dignity that we deserve. Okay, we’re a little crazy to have a Jeep for a daily driver. But if we go off our meds, we might wind up in a Prius"-P.J.O'rourke