These are variations on Ford-Ferguson tractors. Both of these tractors may be 9N models built between 1939 and 1942. Companies other than Ford made these accessories to be bolted onto standard tractors. A total of more than 830,000 of the N model Ford tractors were manufactured between 1939 and 1952. Many of these tractors, now antiques, are still in use around farms. Over the years of production the motor increased in power. The original 9N models came with 20 horsepower motors which later increased to 25 hp in the 8N of 1947-1952. All three early N model Ford-Ferguson and Ford tractors were the same machines with a few changes. These reliable, inexpensive, hard working tractors convinced farmers to move away from farming with horses to mechanizing their farms.
From 1915 to 1939 when the 9N Ford-Ferguson tractor was introduced the number of horses and mules used on American farms had already fallen by half. In 1938 there were 11,163,000 horses and 4,477,000 mules providing power on farms according the U.S. Farm Census. By 1952 when Ford ended production of the popular little 8N tractor the number of farm horses had fallen to 4,330,000 and mules to 1,913,000. When the 9N was introduced by Ford it cost $585 (this is equal to $9,812 in 2015 dollars), not much more than the cost of a single horse.