In the August 2003 Railroad Model Craftsman, on page 80, there is a good explanation of the AB brake system which was common in the '40s. It includes photographs of the basic piping and rodding as applied to a model. The same treatment is given KC brakes, also popular in the 1940s, in the September 2003 RMC, page 78. Both examples show 40' boxcars, but the layout would be the same for most cars of that era.
Wayne