I have a new, but marked up, 92mm Birel Kingpin. I had completely forgotten about it and it looks like it got moisture in the bag and has rust marks on it, but it is not pitted at all, just colored funny.
Pictures here or I can PM them to you. https://www.facebook.com/photo.php?fbid=10160031300910374&set=pcb.214775452421254&type=3&theater&ifg=1
They sell for $32 on Comet https://cometkartsales.com/1.-20.9703.06-King-Pin-Bolt-M8x92-2010.html