Dabba, check with 84CUCV. I'd bet he might even have a wheel or two. Also ask around on CK5. A member there got me a 16" for my spare for shipping a few years back. Before that another one gave me the same deal on a 16.5" wheel when I was running HMMWV tires.
Either that or check
www.car-part.com for junkyards around you. The 16" wheels on a GM 3/4 or 1 ton 8 lug truck from our body style are exactly the same civilian or military. The military's just got painted green.
BTW the 88+ IFS trucks have a very similar backspacing. I have two sets right now and they're pretty much interchangeable with the SFA truck wheels. Look different but they work fine. I know you're aiming more for a restoration though.
Also, at a Pro Mod Bog a spectador told me "that they some times run in addition to different tires (F. to R.) different ratios!! would any one here Know, why they would run different ratios?
They're probably running different sized tires front and rear. I've seen slightly taller tires in the rear and narrower tires in the front before. Think mud dragster. Say 38x11 Boggers in the front and 40" Boggers in the rear. You'd need different gearing to keep them spinning at the same road speed.