I don't think you will find a whole lot of information about the construction of those crew cabs older than '67. They were hand individually hand built by coach builders and I would guess that there were several companies around the US/Canada that built them. Probably all hand crafted like snowflakes.
There are lots of pictures out there, but they all look the same to me. There is a Hemmings article that even OrthMannJ from here posted on..http://blog.hemmings.com/index.php/2008 ... curiosity/
I do like the looks of this 2wd one..