Regarding the 567 original U&V deck, and then the A, B, and C, Kettering's excellent treatise (presented in 1951) on the history and development of the EMD 567 series is available here:
http://utahrails.net/pdf/EMD_5...Development_1951.pdf
The host is utahrails.net.
Kettering (Chief Engineer at EMD in those days) describes most of the design evolution/changes through the years. It is excellent.