'42-'47 1-ton express rear fenders?
 

I'm certain I'll never find original rear fenders for my truck so I was wondering if it would be possible to cut 1/2 ton fenders to the larger wheel profile. I can probably trace the diameter from my front fenders. What I"m not sure of is if the 1-ton fenders are exactly the same overall size as the 1/2 tons...or were they a different item altogether? In some photos they appear to be larger overall. It could just be the angle of the photo, but I thought I would ask the experts!
Thanks fellas.

PS - I've only seen 1/2 ton fiberglass repops, never seen an express truck listed.