I've seen one around somewhere. Ladders for RRC are hard to find because the design of the vehicle doesn't lend itself to one. If you want to see what one looks like watch Camel Trophy '87 on youtube. (Your favorite youtube selection, I know . . . :ylsmoke

They were outfitted with ladders. I don't think you really have to have a ladder for a RRC. I just stand on the tailgate to get to the roof on mine. The sill plates on the doors also work as steps. The roof is low enough to get to all parts of the roof without a ladder in most cases.
David