Farm Jeeps were built, either at the Willys factory, the local dealership or assembled by the owner. The major components that allow the Jeep to function as a light tractor are all bolt-on items. So adding items to your Jeep to make it a Farm Jeep is certainly doable.
John Thompson asked us what he should do to make his 1947 CJ2a (pictured above) a Farm Jeep. We thought it was a great question and have added our response to the Ask Farm Jeep section.