About the only thing that is practical to run with a PTO is some kind of pump or a winch. We used PTO chain driven winches years ago. Unless you want one to be period correct, they have been made obsolete by hydraulic and electric winches. In order to run a flat belt you would probably have to run a shaft to the rear of the vehicle with pillow blocks. PTO's are not made for a pulley mounted directly to them. It would also not be very practical, but. but the whole thing is a hobby. I have a 41 and a 46 GMC 1 1/2 ton. They both have the sliding gear transmissions. PTOs are very rare for these transmissions.
My father got his first PTO on a 1948 model to pump off gasoline. Before that, he had Lawson engines mounted at the back of the truck with brass flex pipe running to the front of the truck to prevent sparks. They had rope starters. Sometimes they started. Sometimes they didn't.
