Thanks for the replies. I had success with the wire wheel and brushing. I do feel inclined to coat the whole trunk with rust reformer and repaint. I am wondering if the spatter paint in there is original for the purposes of color matching it. The car has been repainted in the past and I am not sure if the trunk was done too. Any thoughts?
In my opinion this rust is due to water coming into the trunk as it was parked outside for a significant amount of time. It has, however, been garaged and out of the elements for the past 20 years. There is one spot of rot at the lip of the trunk floor underneath the latch but I would have to remove the bumper to gauge the extent of the problem. The underside of the car needs a lot of help as it spent its life in the midwest. 😑 I hope to start addressing it in the springtime.