It's important to note that the switch and crossing drawings are "typical" and not necessarily an exact drawing of any given prototype. Each company had their own way of using these components.
Note that there are drawings for both BS-95R 95lb rail and BS-85R 85lb rails.
The 95lb rails are by far the most common, corresponding to code75 rail in 4mm/ft scale, and code131 rail in 7mm/ft scale.
A printed paper version of this PDF file is available from the North Eastern Railway Association.
The GWR did not join in the REA and preferred to continue using their existing designs after grouping. BR(W) did start using some REA designs in the 1950s.