Seems that there are several more "Two Unit Pack" assembly manuals that in the wild.
I got a copy of the 8 September 1943 "Manual of Operations for assembling wood cargo bodies packed for export" and it is a treasure chest of wooden body (both G506 and G508!!!!) construction, assembly details and pictures!
Here's a taste:
And it only gets better! I cannot post a copy of the TM as I did not purchase an original.... but WOW.. I am actually giddy. Has pictures of WWII cargo bow corners (oh yeah!) and wiring details for lights and trailer sockets. Some pretty detailed tool box and splash guard diagrams.
It will aid in my reconstruction of my wooden bed for my 43 CCKW. A truly great find.