Yes, there are shelves of parts Russ has made for the six trucks in total. There are THREE different types of construction going on here, and I don't know of one part that is interchangeable with another one. How Russ keeps track of what has been made, what parts need to be made, and where everything is when assembly time comes is amazing!
The REALLY TOUGH nut to crack is going to be raising enough money to purchase 24 wheels and 12 axles to go under those new trucks, so if anyone can help there please do so.