the daruma is a perfectly good way to do it, and will last forever. THe star nut helps speed things up from a production and assembly standpoint. With what I am doing here, we are constantly looking at ways to speed things up without compromising the quality of the final product. WRT the steel washer sandwich on the fender, it is in many ways a belt and suspenders thing. I do it to ad support to the dimple at this mounting point that controls the fender angle. Back to the speed issue, the fender shaping is done unmounted, but once I have the fender-line I want, the dimple is cold set on the bike with the crown mount. I used to do this at the bench with a custom tool, but two 1″ fender washers provide the same support, and saves me time shaping sheet metal at the bench. With fenders like the Berthoud and VO zeppelin that are close to true diameter out of the box the whole process gets even easier.