I have always replaced the 1970's Scamp wrought iron support in my 13's with a more modern looking chrome pole.
Word of caution: This is a roof support so you cannot simply remove it. Many times in trailer rehabs/remodels people will remove the wrought iron because they don't like the way it looks. But you can't do that! Your roof will sag and your door will end up misaligned. Once the roof sags and door misaligns, it will be a lot of work to jack the roof back up and make the repair. If you don't like the look of the wrought iron, change it to something more stylish, as demonstrated in this post!.
I use a heavy duty Chrome closet rod from the Depot and two wood rosettes for the bases.
First step is to apply stain to the rosettes that coordinates with whatever your interior palette might be.
After removing the wrought iron support and using a plum bob to align the rosette and pole location, I glue and screw through from underneath to mount the base rosette to the kitchen counter. Holding the top rosette in place under the top cabinets I take a careful measurement for the pole length and add 1/8" so it maintains a good fit later. After cutting the pole length I place the pole on the bottom rosette, place the top rosette on the pole and tap into place until the pole is level all directions. Then put two screws from the inside of the upper cabinets down into the top rosette and you're done.
I actually added an enhancement to my chrome pole modification. Thinking through the process it was a very simple improvement to add a 1 1/8" Wood Dowel on top of each rosette that bolts through the base cabinet.
You load the top rosette and dowel on the chrome pole and then place the bottom of the pole over the base rosette dowel and then tap it into level and screw the top rosette with two wood screws through the top cabinet.
The trailer will probably implode long before this pole ever goes anywhere now.