I turned this trailer over today, by using a shop crane to lift the tongue, and my Chain Hoist to lift the rear end. A double sheave block was used to stabilize the load.
The first pictures are pictures of improved vertical welds (made with 7018 electrodes). I followed Ernie's advice on making better vertical welds.
Trailer frame was painted with McMaster paint 7725T2, which is zinc based cold galvanizing coating.