Hi Richard,
All that is in Mr. Frank’s book can be found in posts #11 (
http://www.mapleleafup.net/forums/sh...5398#post15398), 18 and 19 (
http://www.mapleleafup.net/forums/sh...1752#post21752) in the CMP Umbauwagen thread. That thread has the most complete info available known to me - believe me, I have looked wide and far. What is good about the sketches is that they give you the basic body dimensions. I reckon the rest can be gleaned from studying the available photos and measuring up the F15 chassis.
Note: the original was based on a Cab 11 F15 4x2, not an F15A. For the general construction method (sheet metal over wooden frame) you would best have a close look at the other German Kfz.15’s. Same for the folding hood.
Many have pondered over and planned for it; I hope someone like you recreates this interesting conversion one day!