For what it's worth, I gave these a shot on Amazon for $300:
https://www.amazon.com/dp/B0DCZMXD33?tag=landcruiserforum-20
Kids were having a hard time getting in and out of the 1958 and I couldn't find anybody willing to ship some take-offs. They arrived within a week from China, were very well packaged, look and feel OEM, and took about 20 minutes to install. As another posted said, the main 12mm bolts that attach the brackets to the running boards are already there... so I just took them out, added some anti-seize, and used them again. The boards connect to the brackets using 10m t-slot hardware. I dabbed blue loc-tite on those threads to ensure they stay in place. Overall, pretty happy with them. Not usually one to buy stuff direct from China.