This was a partial restoration of the exterior only.  The objective was to clean up the rust and give the trailer a coat of paint so it looks clean and tiddy from ten feet.   But as with many projects once underway there were many unseen challenges.  In several places once the rust was ground off there was nothing left to paint.   So the project expanded to include cutting out rusted out sections, replacing them with metal and filling them in with an autobody compound.