I hate picking apart someone else's work, but in the interest of not furthering misinformation:
Page nine has a cut-away view of a KC brake having an integral cut-out cock; this may well be an illustration from the patent for the original H equipment, since K equipment doesn't have this cut-out.
Page ten snows a pictorial view of K brake equipment with the release valve properly shown at the center of the top of the reservoir (the side toward the floor.
Page twelve shows the author's model with the release rod terminating at the triple valve rather than at the aforementioned release valve.
None of the material on AB brakes shows the release valve or its rod at all, On AB equipment the release valve is on the control valve.
Page 21 gives the pipe sizes as the Outside Diameter, while the dimensions cited are actually the trade size of the pipe, the OD (what we model) is larger.
The model observation car has a UC-12 control valve, which hadn't yet been developed when that car was built, and those cars had a short life.
He presents a PC brake diagram, but not PM or LN or UC-12, all much more common systems.
I can't comment on the vacuum brakes.