Seems that just about *any* pioneer tool rack is 'WWII' issue. Even the post WWII war ones that are easily identified as such.
First, a WWII issue pioneer tool rack. They were never issued with a CCKW, but were additional items added as needed. The late 43 CCKWs had the integral tool mounts on the running boards.
picture from http://www.surfacezero.com/g503/showpho ... e=big&cat=
Items to note: leather straps and buckles. Canvas webbing could also be used (repair). The biggest item is the tip of the shovel head. Note the 'u' bracket is made of round bar. That is the #1 tell. Post war/modern racks are identical (save webbing being nylon) but the shovel tip U bracket is FLAT bar, not round.