Well I found it finally. Here's a link to a PDF file containing Very detailed instructions to do this mod. Although they didn't use the back section of the fiberglass roof to cap the rear off. So it looks a little different, but the end result is the same.
I don't see the need to do it, but I can understand the Forest service needing a truck larger than a Jeep but smaller than a regular 1/2 ton truck to get into some tight areas.
Here's the link:
http://www.roscommonequipmentcenter....ects/rec62.pdf