One major problem is the small number of American gun makers and the loss of most and in some cases all of the records. Hard to do a complete story about gun X when the factory is gone, the workers are gone and all the records are gone as well. There are a number of odd, interesting guns that you come across that you just have to wonder about who made them and why they failed.
One area that might make an interesting article is the shells that have been made over the years. Another is the leather cases and accessories. Ever held a nice leather case, well worn from use and tried to figure out how best to restore or keep it or even who made it? I have many modern metal cases but seem to pick leather cases for doubles when ever I travel with them. Period recoil pads could be another interesting subject. There are items not covered yet that are gun related and more knowledge would be a help when we look at guns and try to figure what is original and what is a period upgrade versus a later upgrade. Knowledge is what we are after along with entertainment.