I have a couple different spec books for Mobil stations as well, showing where to place signage on buildings, approved color schemes for stations, etc. They are great references if someone wants to be 100% accurate in the restoration of a station particularly.
I was recently given a Dixie Distributors Inc. binder cover, but unfortunately the internals were all discarded many years ago and it was re-purposed for something else.
It says on the cover "Standard Painting Specifications Trucks - Stations - Pumps". It would have been a goldmine of information for Dixie Oil Company of Michigan collectors.