I think you have a DJ tub on a DJ frame. I think someone got a hold of an old jeep power train and stuck it underneath a genuine DJ. A very rare Jeep to say the least! I would be tempted to try to return it to that status. It would be fairly easy using the surplus of 2 wheel drive postal Jeeps out there. The stopper is the transmission. The two wheel drive transmission could be near impossible to find. The rear tail shaft on the transmission is different because there was no transfer case. The postal jeeps are typically all column shifted and usually right hand steer. There are some left hands out there but, they are rare. Does your steering column look like it used to have a shifter or was it originally a floor shift?

You have a real interesting find no question.