These two useful little booklets contain some notes and series of pictures of GWR wagons, many of them in colour in their preserved condition.
Each picture's caption gives a, sometimes, lengthy description of the wagon portrayed that often includes some history of the vehicle itself.
Volume 1 deals with diagrams A to P, providing a picture, sometimes several, for each one and there are some useful notes on how the goods wagon system worked and on wheels, axles, journals & axle boxes, brakes and bogies.
This covers diagrams from S to AA and DD with some notes on liveries and a couple of pages devoted to Toads, including pictures of a typical interior.
There are no mentions of diagrams Q, R, BB, CC, EE or FF, perhaps ammunition for a third volume?