Have you seen these
 

If you have not already have the following I recommend trying to find them.
Pitmans book The Royal Road by Robert Allan pub in 1946 lots of info about early names and life in transport to end of war...
The Old Motor magazines done in about '60s/70s chock full of info + photos on
Buses, Trucks, Cafés , Vehicles and Engines I only have a few I think they are great
also for modern times ospreycolour books on american trucks, buses etc not seen these for years