Just remember that all the '41 thru '46 cabs are the same cab.. a 2 ton cab is identical to the cab on a 1/2 ton.
You can find people letting the 1.5 and 2 ton'ers go real cheap or even free.
If you do happen to find an old cab at a good price, consult the 'hauling board' over at YesterdaysTractor.com i've sold lots of complete trucks, as well as just cabs to guys who got really low rates on freight from people they hooked up with off YesterdaysTractor.com
The last one was when I sold a 1.5 ton International KB-6.. the guy couldn't find anybody who wanted to mess with it.. but he found a guy on Yesterdays Tractor who showed up with a brand new tractor trailer and a low boy trailer who took that KB6 to Tennessee for $600.
The last cab I sold was off a '39 GMC, it went to a guy in Alabama I think.. he had a regular freight company pick it up, I just had to sit it on a pallet for him.. and I think that only cost him $300.