Then another wooden form would be created to fit into that wooden form. The second form, which now fits perfectly into the first form, would be placed against the second stone. The second stone could be polished until it fit the second wooden form. At that point the first stone would now fit into the second stone and would only have to be moved once. The bed of the bridge needs to be relatively taut to provide a path a human can walk across but the looseness of the side rope should have some impact on its stability.
Gold leaf is a very pliable metal.
Could the elements of the stones have been sanded down or broken down to powder form, then reformed with water into a square mold left to harden. I am surprised at the lack of inquiry in the idea that the water surrounding the Inca empire wasn't used. They had the means and skill to cause those rounded joints, to hammer away by suspending water and rope. The erosion of the rock is already evident, but seems to have been looked over, the rounded rocks used for cutting are obviously eroded by the river, the mountain terrain would've provided the perfect opportunity to build such a system, divert the water and set up a station at which to erode the pre-determined stone. Thanks for any response.