Finally replaced the marker lights and it felt so so good. I ended up having to get non-LED marker lights because of the price but can easily upgrade them in a few years.
We removed the old ones by removing the old lenses, removing the old screws (most rusted and had to be slowly unscrewed with pliers and penetrant), cleaned the area underneath of old adhesive and dirt, make custom rubber gaskets for them found at HomeDepot, and used silicone to seal the hole the wire goes into the trailer. We also used new stainless steel machine screws to attach the lights to the aluminum skin.
I also replaced the reflectors on the front and back sides of the trailer but drilling out the old rivets, cleaning off the old adhesive and dirt, and using new 1/8 aluminum rivets after sticking them on.
The taillight enclosures were badly worn and so I decided to remove them and use new sockets from Vintage Trailer Supply and redo the wiring. I will show you the new ones in another post.
There is also a picture of the old exterior socket that is badly worn and had to be replaced with a new one from HomeDepot.
I also removed the roof vent from the refrigerator, removed the old crumbling sealant, and re-screwed it on with some butyl tape until I decide what to do with it.