The original motion-picture wagon presented a unique challenge; since the story is set in 1810, the model would have to reflect the correct period details missing from the actual movie wagon. The original was built to a design dating from the late 19th century, and includes such period-inaccurate details as iron "patent" hubs, non-wooden axles, and a 3-spring "platform" suspension-system for the front running-gear.
The wagon model is shown as a stake-side wagon, which the movie wagon appears to be, but as is so often the case in movies, what one sees is illusion, not reality; the movie wagon is a light-weight spring-dray (using American wagon terminology), and has no stake pockets on its body; stake pockets are actually mounted on the lower side-rail of the stake-side assembly itself. It appears as though the entire stake-side assembly, cannon-ball rack, tool-box, and probably the front seat, are bolted together and laid saddle-fashion over the flat-bed wagon body in the film.
Another change in the model was to make it represent a heavy-weight wagon, rather than light-weight as the original, so as to be more realistic-looking for the weight of the cargo carried: 11 stone cannonballs. Using the weight of granite as a reference gives a weight for real stone balls, of the estimated size seen in the movie, of 296 pounds, for a total wagon-load of just over 1-1/2 tons American, including toolbox, driver, etc.
I have also used strakes instead of tyres on the wheels, as I don't have the means to weld tyres. In earlier times, both strakes and hoop-tyres were used on wagon wheels, strakes mainly on country vehicles, and hoops more commonly on city vehicles; strakes have a greater tendency to damage hard, paved road surfaces, which would have been more common in cities.
It should be noted that spring wagons such as this are really city vehicles, due to the tight turning radius provided by their small front wheels and body clearance; farm vehicles tend not to have small but larger front wheels, as they generally require the greater ground-clearance given by larger wheels. As the larger wheels cannot turn under the body, the farm vehicles generally have a much larger turning-radius than spring-wagons.
Determining these various details and identifying the actual wagon-type used in the film required single-frame examination of the available film-sequences, and much study of American Horse Drawn Vehicles, by Jack Rittenhouse. Various details found in the Rittenhouse book were adapted to develop the appearance and details of the model, mainly with regard to the running-gear; I do not know if any plans exist for the original wagon.