[Jacques Reed]

Hi Tony,

Yes, I noticed the various Whitworth screws as used on my truck also, mainly on the Holden built body and Australian cab but perhaps I was not clear in my comment.
I was referring to the actual head height of many of the SAE screws and nuts used on the truck. Most are much higher than the currently manufactured ones. See the attached example of two 3/8 UNC screws a commonly used fastener on the truck. New one on the top. Both use 9/16 AF spanners but the height from the bottom of the head to the top of it is higher on the original WW2 manufactured one.

Cheers,

Jacques