As your stated intent to haul dirt caused me to think about weight carrying capability; I think that tongue looks long and slender, (it won't carry a full load of dirt, especially wet dirt!)
Just something to think about...
Sam
I was thinking the exact same thing! When I saw that tongue and also the rust in the corners of the trailer body, I kept thinking one or the other would likely give way under a heavy load at the worst possible moment.
I had an old trailer once, a 4x8, that I tried hauling a load of manure in. Up until then I had thought that old thing was sturdy, a homemade job that I had used for much moving of my home across the state, to several houses, firewood, you name it, I had put it in that old trailer. I thought it was nigh indestructible.
I didn't even get 15 mi. before I had a tire that had rolled off the rim and shredded...pulled over to find that the reason it had done that was that my axle had bent from the heavy load of the manure. And that wasn't wet manure, but very old and very dry manure we had stomped down and piled high.
Had to unload half of it right there by the road, jack up the trailer, take the tire back to the nearest town for repairs, put it back on and proceed the 20 mi. home. Had to return for that other half a load on another day.
That load of manure was my Mother's Day present to myself and my mother...was going to split it with her. I drove her half clear across the state in that swaybacked old trailer.
I'm sure folks living nearby and passing by wondered how a huge pile of manure appeared in that wide spot in the road....and then disappeared a week later.
My old trailer was never the same again and I learned a valuable lesson that day....make sure the trailer fits the load.
I've had to replace a wiring harness twice on the same trailer due to this little problem. 
