the original jib connected to the front crossbar. i can't imagine a clean system that would allow roller furling without eliminating the bridle wire that takes the load of the forestay.
i used to race gcats for the factory and pretty much everyone that gets beaten by one goes into denial about how good and fast gcats are.
now that cats have spinakers the downwind superiority of gcats is prolly gone, but before the spi. gcats could bring the apparent wind forward and still bear way off much better than the other cats whilst tacking downwind.