Hi Dean, this is Dean! ;-) I don't get to say that often!
Welcome to the VCCA's website!
Is your truck a 1/2 ton? The one ton trucks have a smaller engine compartment, so the fan is right up to the back of the radiator. The 1/2 ton's engine compartment is 4 inches longer than the one ton's, thus the need for the shroud.
I have not looked for such a shroud (my '28 Canopy Express came with its original shroud - see Justin's link below), but I do take notice of '28 parts for sale and have only seen a couple of shrouds come up for sale in the last 10 years or so.
There happens to be one for sale on ebay right now. Here it is:
https://www.ebay.com/itm/125184197531What other parts are you looking for?
Cheers, Dean