Bob, they are hard enough you can either use GOOD body filler or epoxy for flexable bumper repair or something like Lord Fusior. The ones on the Twenty I am working on was in good shape exept that had some scratchs and have been painted over. I have repaired many a cracked steering wheel on wheeled tractors using the epoxy first to fill the major cracks and then a fine layer of body filler to give it the finsh coat before prime and painting.
Terry
No complaining on titles here.