Need help to indentify this tractor

[rustydollar]

I wonder if it started life as an industrial tug?

I now believe it started life as a Postal Jeep, engine is GM nick named the Iron Duke both Mercruiser and OMC had marine versions, the valve cover on the tractor engine gives it away.

The protruding axle nut on the rear differential screams JEEP.

 

[GLyford]

AM General made other stuff besides jeeps, including logistics equipment, but yeah, probably a good bet.