The materials list and information here is nice to have.
This is the really important part ...
making the bends.
Using this information from page 150 you can make any number of different carts. The axle plates are made with plain electrical box covers that have no punch-outs, and have corner slots for screws (which in the diagram have been cut off). If you need more information about the axle plates, click on the link to axles or freighter cart plans and it will take you to that blog entry.