That's very like how the CRC car mounts it's football...it uses thin 4-40 nuts like you describe on the links. I'd prefer sticking with the stock steel ball though for ease of maintenance. Brass and aluminum balls pit out fairly quickly in certain conditions and need a lot of maintenance to keep running smoothly. I was constantly having to repolish the pivot balls on my EV10 back in the day. the new steel ones that Darkside and CRC are using are so much smoother and maintenance free...it's a big relief.