One of the things that makes the 20,000th Diesel RD-4...
As anyone that has attempted one will confirm, tractor restorations are hard. With any challenging task, one good way to find motivation to continue is to visualize what life after the finish line looks like. Chuck Ehler encountered several obstacles in his quest to find and restore the 20,000th Caterpillar Diesel RD-4, and one idea for after it was done helped him persevere to complete the project.
