That pulley set-up looks like it was purpose made for that Model T application... a commercial manufactured item. They did make a lot of aftermarket stuff for "T's"I took a minute to photo this pulley.
it is a 21 inch demount-able wheel from a 26 T car.
I doubt the car would be driven very far with this installed. The owner probably would have just putt putted around the farm in low gear.
This is hub,brake drum and all. I have no knowledge of the history of this as it was just handed to me 1 day at a tech session with the model T club I am in. They know I gather odd stuff!.