[Alex van de Wetering]

Ed, Thanks for taking the time to look into this.

I have purchased copies the first two pamphlets you mentioned; Pamphlet no. 2, dated 1939 and Pamphlet no. 13, dated 1945.
The former shows some diagrams of very early trucks FBE trucks, which are not the ones I am after, but nonetheless interesting to add to this thread.
The latter does show the trucks with the 4 pillars, but only as a picture, not the diagrams that David posted here years ago.