That Razor Dune Buggy spindle kingpin bolts are 10mm OD and the Razor kick scooter axle bolts are 8mm OD so the kick scooter axles will not work as replacements.
We have a source for these type of bolts in 10mm OD and various lengths. I will need to take some measurements of the kingpin bolts to make sure we can get the exact same size though.
If we can order these kingpin bolts it would take a couple of weeks for them to arrive. I will take some measurements this week and let you know if we can get them, and if we can then I will post a link to the page where they can be purchased.
I've ordered some $.48 sleeve bearing bushings from mcmaster will update if they work out.